Fibromuscular dysplasia

A case report with literature review: long-term follow-up of kidney autotransplantation in fibromuscular dysplasia

Fibromuscular dysplasia is a rare, idiopathic, systemic, non-inflammatory, and non-atherosclerotic vascular disease that primarily affects young women. It often presents as renal artery stenosis. Fibromuscular dysplasia can induce tissue damage in the post-stenotic kidney. Treatment options include antihypertensive therapy, surgical revascularization, and transluminal angioplasty with stent implantation. However, kidney autotransplantation is an alternative when these treatments are not feasible. This study presents a case report of a 22-year-old woman with fibromuscular dysplasia, highlighting the long-term success of kidney autotransplantation and reviewing the related literature. A multidisciplinary approach was employed in the treatment of this patient presenting with intermittent headaches, hypertension, and acute kidney disease, and who was diagnosed with fibromuscular dysplasia. She underwent left aorta-renal bypass and right autotransplantation. Following the procedure, her serum creatinine level decreased from 2.74 to 1.1 mg/dL, with an eight-year follow-up confirming the favorable outcome. Renal artery stenosis is a significant contributor to secondary hypertension, with fibromuscular dysplasia being a rare cause. While medical and interventional treatments are usually effective, complex cases may necessitate alternative approaches. Kidney autotransplantation, albeit uncommon, is an effective option for patients who are unresponsive to conventional therapies. This case demonstrates the successful management of fibromuscular dysplasia-associated renovascular hypertension via kidney autotransplantation, resulting in controlled blood pressure and preserved kidney function. In conclusion, kidney autotransplantation represents a valuable therapeutic option for severe renal artery stenosis caused by fibromuscular dysplasia, particularly when percutaneous procedures are impractical.

Charting the Unseen: How Non-Invasive Imaging Could Redefine Cardiovascular Prevention

Cardiovascular diseases (CVDs) remain a major global health challenge, leading to significant morbidity and mortality while straining healthcare systems. Despite progress in medical treatments for CVDs, their increasing prevalence calls for a shift towards more effective prevention strategies. Traditional preventive approaches have centered around lifestyle changes, risk factors management, and medication. However, the integration of imaging methods offers a novel dimension in early disease detection, risk assessment, and ongoing monitoring of at-risk individuals. Imaging techniques such as supra-aortic trunks ultrasound, echocardiography, cardiac magnetic resonance, and coronary computed tomography angiography have broadened our understanding of the anatomical and functional aspects of cardiovascular health. These techniques enable personalized prevention strategies by providing detailed insights into the cardiac and vascular states, significantly enhancing our ability to combat the progression of CVDs. This review focuses on amalgamating current findings, technological innovations, and the impact of integrating advanced imaging modalities into cardiovascular risk prevention, aiming to offer a comprehensive perspective on their potential to transform preventive cardiology.

Moyamoya Vasculopathy and Moyamoya-Related Systemic Vasculopathy: A Review With Histopathological and Genetic Viewpoints

Systemic vasculopathy has occasionally been reported in cases of moyamoya disease (MMD). Since the pathological relationship between moyamoya vasculopathy (MMV) and moyamoya-related systemic vasculopathy (MMRSV) remains unclear, it was examined herein by a review of histopathologic studies in consideration of clinicopathological and genetic viewpoints. Although luminal stenosis was a common finding in MMV and MMRSV, histopathologic findings of vascular remodeling markedly differed. MMV showed intimal hyperplasia, marked medial atrophy, and redundant tortuosity of the internal elastic lamina, with outer diameter narrowing called negative remodeling. MMRSV showed hyperplasia, mainly in the intima and sometimes in the media, with disrupted stratification of the internal elastic lamina. Systemic vasculopathy has also been observed in patients with non-MMD carrying the RNF213 (ring finger protein 213) mutation, leading to the concept of RNF213 vasculopathy. RNF213 vasculopathy in patients with non-MMD was histopathologically similar to MMRSV. Cases of MMRSV have sometimes been diagnosed with fibromuscular dysplasia. Fibromuscular dysplasia is similar to MMD not only in the histopathologic findings of MMRSV but also from clinicopathological and genetic viewpoints. The significant histopathologic difference between MMV and MMRSV may be attributed to a difference in the original vascular wall structure and its resistance to pathological stress between the intracranial and systemic arteries. To understand the pathogeneses of MMD and MMRSV, a broader perspective that includes RNF213 vasculopathy and fibromuscular dysplasia as well as an examination of the 2- or multiple-hit theory consisting of genetic factors, vascular structural conditions, and vascular environmental factors, such as blood immune cells and hemodynamics, are needed.

Spontaneous coronary artery dissection: review, case report and analysis of COVID-19-related cases

Spontaneous coronary artery dissection (SCAD) accounts for 1-4% of all acute coronary syndromes (ACS). Since the first description in 1931, our understanding of the disease has evolved; however, its pathophysiology and management are still a matter of debate. SCAD typically occurs in a middle-aged woman with no or few traditional cardiovascular risk factors. Two hypotheses have been proposed to explain the pathophysiology depending on the primary event: an intimal tear in the "inside-out" hypothesis and a spontaneous hemorrhage from the vasa vasorum in the "outside-in" hypothesis. Etiology appears to be multifactorial: different predisposing and precipitating factors have been identified. Coronary angiography is the gold standard for the diagnosis of SCAD. Current recommendations on the treatment of SCAD patients are based on expert opinions: a conservative strategy is preferred in hemodynamically stable SCAD patients, while urgent revascularization should be considered in hemodynamically unstable patients. Eleven cases of SCAD in COVID-19 patients have already been described: although the exact pathophysiological mechanism remains unclear, COVID-19-related SCAD is considered a combination of significant systemic inflammatory response and localized vascular inflammation. We present a literature review of SCAD, and we report an unpublished case of SCAD in a COVID-19 patient.

Cerebral arteriopathies of childhood and stroke - A focus on systemic arteriopathies and pediatric fibromuscular dysplasia (FMD)

Systemic vascular involvement in children with cerebral arteriopathies is increasingly recognized and often highly morbid. Fibromuscular dysplasia (FMD) represents a cerebral arteriopathy with systemic involvement, commonly affecting the renal and carotid arteries. In adults, FMD diagnosis and classification typically relies on angiographic features, like the 'string-of-beads' appearance, following exclusion of other diseases. Pediatric FMD (pFMD) is considered equivalent to adult FMD although robust evidence for similarities is lacking. We conducted a comprehensive literature review on pFMD and revealed inherent differences between pediatric and adult-onset FMD across various domains including epidemiology, natural history, histopathophysiology, clinical, and radiological features. Although focal arterial lesions are often described in children with FMD, the radiological appearance of 'string-of-beads' is highly nonspecific in children. Furthermore, children predominantly exhibit intimal-type fibroplasia, common in other childhood monogenic arteriopathies. Our findings lend support to the notion that pFMD broadly reflects an undefined heterogenous group of monogenic systemic medium-or-large vessel steno-occlusive arteriopathies rather than a single entity. Recognizing the challenges in categorizing complex morphologies of cerebral arteriopathy using current classifications, we propose a novel term for describing children with cerebral and systemic vascular involvement: 'cerebral and systemic arteriopathy of childhood' (CSA-c). This term aims to streamline patient categorization and, when coupled with advanced vascular imaging and high-throughput genomics, will enhance our comprehension of etiology, and accelerate mechanism-targeted therapeutic developments. Lastly, in light of the high morbidity in children with cerebral and systemic arteriopathies, we suggest that investigating for systemic vascular involvement is important in children with cerebral arteriopathies.

Spontaneous coronary artery dissection and fibromuscular dysplasia: insights into recent developments

Spontaneous coronary artery dissection (SCAD), an uncommon cause of acute coronary syndrome, continues to be a poorly understood disease predominantly affecting females. It is characterized by an abrupt separation in the coronary arterial wall due to intramural bleeding. Fibromuscular dysplasia (FMD) is a non-atherosclerotic arteriopathy manifesting in medium and small-sized arteries. It is a concomitant disease found among SCAD patients. In some studies, FMD prevalence in SCAD patients ranges between 25%-86%, which can be explained through varying screening techniques or modalities. The potential association has been elucidated in some studies; notably, not only has a genetic link been recently delineated between SCAD and FMD, but there is data to suggest that FMD not only can predispose to SCAD but can also be a potential predictor of its recurrence. However, a clear-cut correlation between the two has still not been established due to conflicting reports in the literature. To further dive into its pathology, it is crucial to highlight the importance of systematic screening in SCAD in order to identify associated risk factors and to be used as a method of FMD detection in such patients. Together, the two pathologies pose unique challenges in understanding its pathophysiology, diagnosis and management, as there is no clear evidence of a definitive treatment plan for patients with SCAD and FMD. A potentially beneficial modality of management is physical exercise, which is currently understudied in the long-term approach to treatment for patients with concomitant SCAD and FMD. Limited research in this field brings disadvantages to the understanding of the association between these two diseases, in order to give rise to better management recommendations. This mini-review aims to highlight the recent developments in the association between SCAD and FMD, its potential genetic association and some insights in screening, diagnosis, and management.

Intrinsic stenosing and occlusive pathologies of the vertebral artery: A narrative review

Intrinsic pathologies of the vertebral arteries, such as atherosclerosis, dissection, fibromuscular dysplasia, radionecrosis and vasculitis, are important causes of vertebrobasilar insufficiency and cerebrovascular events. This review focuses on non-aneurysmal intrinsic stenosing and occlusive pathologies, covering their epidemiology, diagnosis, and treatment options. It also provides a detailed summary of key clinical presentations and syndromes, including an in-depth examination of lateral medullary syndrome, historically known as Wallenberg's syndrome, which is arguably the most emblematic condition resulting from vertebral artery involvement and is depicted in an illustrative cartoon.

Fibromuscular dysplasia of the coronary arteries: An unusual case of sudden death and review of the literature

Fibromuscular dysplasia of the coronary is an uncommon coronary defect with a range of pathological alterations and unpredictable clinical description that can cause sudden death. We present an autopsy case of sudden cardiac death due to a rupture of a coronary artery aneurysm in a 59-year-old woman. Postmortem autopsy revealed two huge saccular aneurysms located at the right coronary artery, one of which was ruptured leading to a fatal hemopericardium. Histopathological examination revealed coronary artery fibromuscular dysplasia with fibromyxoid dissociation of the media causing saccular aneurysms. The involvement of coronary arteries in fibromuscular dysplasia with aneurysmal features has been rarely reported in the literature and is most likely an underdiagnosed finding. Due to the little number of published studies, the etiology is not fully understood and data on pathogenesis, risk factors, manifestation, disease course, and mortality are still unclear, which is a gap that needs to be filled in order to avoid under-diagnosis of the disease. Our case report aimed to discuss the mechanisms of sudden death attributed to coronary fibromuscular dysplasia.

Prevalence and clinical characteristics of renovascular hypertension associated with fibromuscular dysplasia in China

OBJECTIVES

The aim of this study was to investigate the clinical characteristics of renal artery fibromuscular dysplasia (FMD) in patients in China and identify the cure rate of hypertension after angioplasty.

METHODS

Consecutive hypertensive patients with renal artery stenosis caused by FMD who underwent catheter-based angiography, and were followed at two Chinese referral centres, were retrospectively analysed. All patients underwent a detailed investigation, including demographic characteristics, clinical characteristics, biochemical sampling, Doppler ultrasonography of carotid arteries, magnetic resonance angiography (MRA) of the intracranial artery, and CTA or MRA of the abdominal artery and catheter-based renal angiography. Patients were routinely followed up at 1 month, 6 months and every year after the procedure.

RESULTS

Among 245 study participants, with a mean diagnosed age of 26.9 ± 9.9 years, 137 (55.9%) were women, and 38 (15.5%) were children. All patients were diagnosed with hypertension at a mean age of 23.4 ± 8.4 years. There were 73.5% focal and 15.2% multivessel cases. Aneurysms, arterial dissections and total occlusions were found in 21.6, 4.1 and 12.2% of patients, respectively. Patients with multifocal FMD were older (26.0 vs. 23.7 years, P  = 0.021) and more often female (70.8 vs. 50.6%, P  = 0.004). Among children with renal FMD, 55.2% were men, and 86.8% were focal. After a median follow-up of 7.0 years, multifocal FMD had a higher cure rate of hypertension than focal FMD after revascularization (71.7 vs. 55.8%, P  = 0.032).

CONCLUSION

In a cohort of mostly young Chinese patients, the prevalence of hypertension associated with renal FMD is similar in both sexes. Focal FMDs were more frequent than the multifocal ones and, after angioplasty, were associated with a worse blood pressure outcome.

Fibromuscular Dysplasia Presenting as Acute Unilateral Renal Infarction: A Case Report and Review of Two Diseases

Fibromuscular dysplasia (FMD) is a rare systemic vascular disease that has been found to present as a renal infarction (RI) in only a handful of cases.  We present a case of a 53-year-old Vietnamese patient presenting for sharp, severe left-sided abdominal pain of two-day duration associated with a migraine headache. On presentation, she was afebrile, and her vital signs were stable. Laboratory investigations were significant for mildly elevated leukocytosis but were otherwise normal. CT abdomen and pelvis with contrast revealed a left-sided renal infarct. The patient was then admitted to the hospital and started on therapeutic anticoagulation. A transthoracic echocardiogram was obtained and revealed no vegetation. CT angiography of the abdomen was pursued and was significant for mild beading within the mid-right and left renal arteries, consistent with fibromuscular dysplasia. Our patient was diagnosed with renal infarction in the setting of fibromuscular dysplasia, a combination that has been reported only a few times. Interestingly, our patient also had mild FMD based on imaging, making it even more of an unusual cause of renal infarction. This case highlights the connection between these two diseases and the need for more studies to characterize the association between them.

Intravascular ultrasound provides additional insights in the hypertensive patients with focal renal artery fibromuscular dysplasia

To date, few study has defined the exact role or utility of intravascular ultrasound (IVUS) in the diagnosis and treatment of renal artery fibromuscular dysplasia (FMD). We investigated whether using an IVUS would provide additional insights in the hypertensive patients with focal renal artery FMD. A prospective, observational study, including all patients with focal renal artery FMD admitted to the Ruijin hospital during 6 consecutive years (2015-2021). Based on IVUS imaging, focal FMD patients were classified as two subtypes: intima-media thickening (IMT) and negative remodeling (NR) of the whole vessel. A total of 36 consecutive patients (24 ± 7, 13-39 years) with focal renal artery FMD were enrolled. Angiographic unifocal type was present in 22 (61.1%) patients and tubular type was present in 14 (38.9%) patients. Among 22 patients with unifocal, IVUS showed that 18 (81.8%) had IMT and 4 (18.2%) had NR. 14 patients with tubular, IVUS showed 3 (21.4%) had IMT and 11 (78.6%) had NR. No difference in age of onset, gender, BMI, initial BP levels were found between IMT and NR subtypes. However, hypertension cure rates of short-term (48 h after angioplasty) (76.2% vs. 26.7%, p = 0.004) and long-term (1-6years) (90.5% vs. 20.0%, p < 0.001) were higher in patients with IMT than in those with NR subtype. In present study, we described a new classification of focal renal artery FMD into IMT or NR subtype based on IVUS. Renal FMD Patients with IMT subtype were more likely to achieve cure of hypertension. We investigated whether using an IVUS would provide additional insights in the hypertensive patients with focal renal artery FMD. A new classification of focal renal artery FMD into IMT or NR subtype based on IVUS was described. Renal FMD Patients with IMT subtype were more likely to achieve cure of hypertension.

Multimodal imaging approach in hyponatremic hypertensive syndrome. A rare case of pediatric unilateral hypoplasia of the main renal artery combined itself with stenosis and review of literature

Renal artery stenosis (RAS) accounts for approximately 5%-10% of secondary renovascular hypertension in the pediatric population. It can occur as an isolated entity, or as a hypoplasia combined itself with stenosis. Hypoplasia, or long-segment developmental narrowing, is a rare cause of renovascular hypertension. Hyponatremic hypertensive syndrome (HHS) is a malignant complication of unilateral RAS and/or renal artery hypoplasia. Hyponatremia, hypokalemic hypochloremic metabolic alkalosis, nephrotic range proteinuria, polyuria, polydipsia, and weight loss are the most common findings. In particular, hypertension remains refractory despite aggressive antihypertensive therapy. Laboratory findings of elevated plasma levels of renin in most case suggest that the stimulation of renin release from the ischemic kidney plays an important pathophysiologic role. HHS is a diagnostic and therapeutic challenge in children. We report a case of a unilateral right renal artery hypoplasia, complicated by a segmental narrowing, in a 17-month-old male, clinically symptomatic for hypertension. We emphasize the role of ultrasound, computed tomography, and digital subtraction angiography that should be planned as reliable and non-invasive multimodal imaging approach.

Percutaneous Transluminal Renal Angioplasty for Fibromuscular Dysplasia and Prognostic Risk Factors: A Retrospective Chinese Cohort Study

Fibromuscular dysplasia (FMD) is a non-atherosclerotic, non-inflammatory vascular disease involving small-to-medium-sized arteries. The characteristics of Chinese patients with FMD remain unclear. We retrospectively analyzed the data of patients with renal FMD who underwent percutaneous transluminal renal angioplasty (PTRA) for the first time at Fuwai Hospital between 2010 and 2021. The variables were selected through least absolute shrinkage and selection operator regression (LASSO), and logistic regression models were constructed to identify independent risk factors. A total of 116 patients (52 males, median age at diagnosis, 25.0 years) were enrolled. Elevated blood pressure was the leading complaint. After a median follow-up period of 18.0 months (interquartile range: 6.0-48.0 months), hypertension recurred in 34 patients and restenosis in nine patients, among whom four patients underwent secondary intervention and one patient underwent surgical revascularization. Bilateral renal artery involvement (odds ratio [OR]: 2.61, 95% confidence interval [CI]: 1.11-6.15; p = 0.028) and age at hypertension onset (OR: 0.93, 95% CI: 0.88-0.99; p = 0.018) were independent prognostic factors for adverse outcomes. The results indicate that patients with bilateral renal artery involvement and younger age at hypertension onset are more likely to have poorer clinical outcomes after PTRA, and should be more closely monitored.

2 Cases of Spontaneous Coronary Artery Dissection in Neonates

Spontaneous coronary artery dissection in infants is a rare phenomenon. We present 2 neonates with severe ventricular dysfunction due to coronary artery dissection. Neither patient had evidence of extracardiac fibromuscular dysplasia or other comorbidities that would explain the presentation. (Level of Difficulty: Advanced.).

Mesenteric Artery Dissection and Wall-Thickening, Case Study and General Review

Mesenteric artery dissection (D) and wall-thickening (WT) are rare vasculopathies that can lead to serious complications. This is a single center analysis of all patients evaluated for mesenteric arterial (celiac, superior (SMA) and/or inferior mesenteric (IMA)) D and/or WT from January 1, 2000, to January 31, 2020 at our hospital. Among the 101 included patients, the average age was 55.6 ± 13.6 years, mostly affecting men (62%). There were 20 celiac artery D, 8 WT, 15 D with WT, 15 SMA D, 7 WT, 8 D with WT, one IMA D, two WT, and 25 with multiple arterial involvement. Primary etiologies included segmental arterial mediolysis (SAM) (n = 17), isolated D (n = 17), localized vasculitis of the gastrointestinal tract (LVGT) (n = 16), fibromuscular dysplasia (FMD) (n = 13), extension of thoracoabdominal aortic D (n = 12), and trauma (n = 12). Most (71%) patients presented with abdominal pain. Hypertension (55%), hyperlipidemia (33%) and tobacco use (31%) were prevalent. Management included conservative (22%), medical (47%), endovascular (19%), and/or open repair (12%) with high in-hospital survival (98%) and symptom relief (73%). Our paper complements the scarce literature addressing the diagnosis and management of rare mesenteric vasculopathies. Most patients improved with conservative management, reserving endovascular or surgical interventions for symptomatic patients with more complicated presentations.

Aortic Dimensions Are Larger in Patients With Fibromuscular Dysplasia

Background Fibromuscular dysplasia (FMD) is a disease of unknown etiology that causes stenosis, aneurysmal dilatation, and dissection of vascular beds. Known to affect medium-sized arteries, FMD is not typically considered to affect the aorta. We tested the hypothesis that aortic size in FMD is abnormal compared with age- and sex-matched controls. Methods and Results Medical records and computed tomography angiography images were reviewed in female patients with a diagnosis of FMD who were seen in the vascular medicine clinic at Emory Healthcare. Aortic dimensions were measured at 6 different landmarks. Using 2 sample t tests, the aortic measurements and height-indexed measurements were compared with published normal values in healthy women of a similar age. A total of 94 female patients were included in the study. The median age was 57 (interquartile range, 50-65). FMD involvement was present most commonly in the extracranial carotid (77.7%) and renal (43.6%) arteries. All 6 aortic segments were found to be larger in both absolute measures and height-indexed measures in the FMD population (P<0.001). The largest differences were observed within the absolute measures of the sinotubular junction with mean±SD (mm) (29.9±4.1) versus (27±2.5), ascending aorta (32.7±4.4) versus (30.0±3.5), and descending aorta (24.7±3.0) versus (22.0±2.0) (P<0.001). Conclusions Aortic diameters in female patients with FMD are larger when compared with published age- and sex-matched normal values. These findings suggest that FMD may also affect the large-sized arteries.

Neurosurgical Causes of Pulsatile Tinnitus: Contemporary Update

Traditionally in the domain of the otolaryngologist, pulsatile tinnitus (PT) has become increasingly relevant to neurosurgeons. PT may prove to be a harbinger of life-threatening pathology; however, often, it is a marker of a more benign process. Irrespectively, the neurosurgeon should be familiar with the many potential etiologies of this unique and challenging patient population. In this review, we discuss the myriad causes of PT, categorized by pulse-phase rhythmicity.

A case of fibromuscular dysplasia related intracerebral hemorrhage without angiographically cerebral abnormal vessels

Background:

Fibromuscular dysplasia (FMD) can cause cerebral aneurysms and dissection, which can lead to stroke. Angiographic findings are important in the diagnosis. We report a case of FMD in which the cause of hemorrhage could not be determined by angiography.

Case Description:

A 73-year-old woman suffered from intracerebral hemorrhage (ICH) associated with FMD without abnormal angiography cerebral vessels. She presented with headache and nausea. Subsequent head-computed tomography-revealed ICH in the left frontal lobe, and contrast-enhanced magnetic resonance imaging revealed a gadolinium-enhancing lesion in the perihematoma area and in the genu of the corpus callosum. Although cerebral angiography revealed a string of beads appearance in the bilateral extracranial internal carotid arteries, no abnormality explaining the hemorrhage was identified. The hematoma was removed and the pathological diagnosis was FMD. In the pathological specimen, various patterns of vulnerable vessels, such as aneurysmal dilatation and obstruction, were observed, which could easily collapse and result in hemorrhage. In the case of ICH of unknown origin, microscopic vessel disruption due to FMD should also be considered.

Conclusion:

FMD can cause ICH in microscopic vascular lesions that are undetectable on angiography.

Case Report: Combination of Pressure Guidewire and Optical Coherence Tomography-Guided Drug-Coated Balloon Revascularization for Renal Artery Fibromuscular Dysplasia

Fibromuscular dysplasia (FMD) is the second common cause of renovascular hypertension. With the advent of endovascular therapy, angiography has become a diagnostic gold standard for FMD. Optical coherence tomography (OCT) by reflecting in vivo histology may improve diagnostic and classification accuracy. Renal fractional flow reserve (rFFR), measured by pressure guidewire, may distinguish the patients who may benefit from revascularization by identifying physiologically significant stenoses. However, the role of usage of both OCT and rFFR is not well-studied. We herein report a 17-year-old male with renovascular hypertension due to FMD. Angioplasty of drug-coated balloon (DCB) guided by OCT and FFR favorably achieved blood pressure (BP) control. In conclusion, the utility of both OCT and FFR may be useful for the appropriate selection of patients with renal FMD.

Frequency of recurrence of peripheral artery disease among angioplasty and stenting patients

Background

Peripheral artery disease (PAD) is a cardiovascular disease that is characterized by obstruction of peripheral artery. It is associated with comorbidities, reduced quality of life and mortality. The aim of this study was to determine the frequency of recurrence of PAD among patients who underwent angioplasty or stenting and associated risk factors.

Methods

In this retrospective study, all patients referred to the cardiovascular center of (XXX) with the diagnosis of lower extremity PAD were included. Patients’ demographic information, age, gender, smoking status, history of diabetes, history of hypertension, dyslipidemia, number of vessels, type of stent, recurrence of the disease, and size of the lesion were obtained from the hospital database. Endovascular revascularization therapy was either performed by angioplasty or stenting method. The data were analyzed by SPSS v21.

Results

Of 88 patients included in this study, 12.5% were reported with restenosis. Gender, age, size of the lesion, the status of smoking, history of hypertension, and dyslipidemia were not significantly associated with the recurrence of stenosis, p > 0.05. There was a significant relationship between the vessels involved and the type of revascularization method and the recurrence of the PAD.

Conclusion

Endovascular revascularization technique and type of vessel involved in PAD are significant factors contributing to restenosis in our population of study. However, further studies with a greater sample size are required in this area.

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Peripheral artery disease is a cardiovascular disease with obstruction of peripheral artery.

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It is associated with comorbidities, reduced quality of life and even mortality.

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Endovascular revascularization technique in PAD are significant factor in our study.

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However, further studies with greater sample size are required in this area.

Mid-term outcome of angioplasty for pediatric renovascular hypertension

PURPOSE

To evaluate the mid-term outcome of percutaneous transluminal renal angioplasty (PTRA) for pediatric renovascular hypertension (RVH).

MATERIALS AND METHODS

The clinical data of patients who underwent PTRA for RVH in our hospital from 2012 to 2019 were analyzed retrospectively. Post-procedural blood pressure, glomerular filtration rate (GFR) of the affected kidney, restenosis and complications were closely followed up.

RESULTS

The procedure of PTRA was performed in total of 30 children (20 males and 10 females), with a mean age of 7.32±0.74 years (40 days ∼13.92 years) and a mean weight of 24.99±2.26 kg (3.4 ∼ 53kg). The median follow-up period was 26.5 months (1 month ∼7.5 years). Technical success was achieved in 26 of 30 patients (86.7%). Three patients (10.0%) developed restenosis. Only 1 patient underwent stent implantation, and the stent fractured 8 months later, requiring further intervention. No other complication was found. In terms of clinical benefit of blood pressure control after the initial PTRA procedure, 15 patients (50%) were cured and 7 (23.3%) improved. There was no significant difference in etiology, lesion location and length between patients with clinical benefit and failure (p=0.06, 0.202 and 0.06). The GFR of the affected kidney was significantly improved from 19.85±11.24 (ml/min) to 38.09±11.88 (ml/min) at 6 months follow-up after PTRA (p<0.001).

CONCLUSION

The overall results of PTRA for pediatric RVH caused by different etiologies are promising. Not only does it provide clinical benefit of blood pressure control in 73.3% of patients, it also significantly improves the function of the affected kidney.

High prevalence of extrarenal artery involvement in children with fibromuscular dysplasia - a single-center experience

BACKGROUND

Although the clinical presentation of fibromuscular dysplasia (FMD) and its generalized character has been previously described in adults, data on FMD in children are limited.

METHOD

In this study, we aimed to assess visceral artery involvement in pediatric FMD patients with documented renal artery stenosis (RAS) and renovascular hypertension (RVH) in comparison with healthy individuals. We retrospectively analyzed the results of angiographic studies of 16 patients with a median age of 13.9 years (10 girls) in comparison with 16 age- and sex-matched healthy controls.

RESULTS

Out of the 16 FMD patients, 10 (63%) had stenotic lesions identifiable only in renal arteries, whereas six (37%) had additional stenoses in other vascular beds - in the celiac trunk (four patients), superior mesenteric artery (four patients), inferior mesenteric artery (one patient), splenic artery (one patient), common hepatic artery (three patients), and abdominal aorta (one patient). The comparison of ostial diameters of vessels, in which no periostial narrowing, stents, or occlusions were found, revealed that patients with FMD had a significantly smaller diameter of the celiac trunk (P = 0.017), splenic arteries (P = 0.007), and common hepatic artery (P = 0.026) than their age- and sex-matched healthy peers.

CONCLUSION

We found that 69% of children with RVH caused by FMD had clinically silent stenoses or tortuosity of visceral arteries. The results of our study suggest that pediatric FMD is a generalized arterial condition, and the patients may need screening for both renal as well as nonrenal manifestations of the disease.

Ruptured Left Gastric Artery Aneurysm Associated with Fibromuscular Dysplasia

Background: Fibromuscular dysplasia is a non-inflammatory, non-atherosclerotic vascular disease that commonly affects renal and carotid arteries but involvement of virtually any vascular territory has been observed.Research Design/ Study sample: This is a case report of a ruptured left gastric artery aneurysm as the first presentation of fibromuscular dysplasia.Data collection: After written consent from the patient, relevant clinical notes and imaging were retrospectively reviewed and critically analysed.Purpose: This case reiterates the importance of considering fibromuscular dysplasia as an uncommon cause of visceral artery aneurysms. In addition, this case shows that the impact of visceral artery vasospasm on endovascular access should not be underestimated and subsequent attempts can be successful after a period of resuscitation.Results: After initial difficulty in endovascular treatment due to visceral vasospasm, the case was successfully managed with with staged open ligation and endovascular embolization after a period of resuscitation.Conclusions: FMD is an important differential diagnosis to consider in cases of visceral aneurysms.

Insights from intravascular pressure measurement of renal artery revascularization in patients with fibromuscular dysplasia: the DYSART study

OBJECTIVE

The indication of percutaneous renal transluminal angioplasty (PTRA) in fibromuscular dysplasia (FMD) is mainly based on renal artery stenosis (RAS) due to atherosclerosis criteria, which are not specific to FMD. Consequently, the selection of patients who could benefit from this treatment and its effectiveness remain uncertain. The aims of this study were to: (1) report the effects of PTRA guided by trans-stenotic pressure measurements on hypertension 7 months after treatment; (2) assess the impact of pressure measurement to guide treatment efficacy in comparison to visual angiographic parameters; and (3) evaluate the reproducibility and accuracy of the stenosis measurement using a 4F catheter in comparison to a pressure guidewire.

METHODS

This prospective multi-centric study analyzed 24 patients with hypertension with RAS due to FMD that required PTRA. Clinical, duplex ultrasound, and angiographic indices were collected, and patients were followed up for 7 months (±1 month). Angiographic indices were measured twice both by a pressure guidewire and a 4F catheter. Assessment of procedural and clinical success of angioplasty was performed for all patients.

RESULTS

Twenty-three patients (96%) had procedural success (considered as a post-PTRA translesional systolic gradient ≤10 mmHg or reduced by at least 80%) with a significant decrease in the systolic gradient after angioplasty (26.50 mmHg; [interquartile range, 16.75-38.75] vs 0.00 [interquartile range, 0.00-2.00]; P < .01). Three patients (12%) had complications, including two renal artery dissections and one partial renal infarction. Twenty-one patients (88%) were clinical responders to angioplasty at follow-up. Visual stenosis assessment showed a poor correlation with systolic gradient measurement before and after PTRA (R from -0.05 to 0.41; P = 0.06-0.82). High correlations were found between pressure measurements made by a 4F catheter and guidewire (R from 0.64 to 0.89; P ≤ .003).

CONCLUSIONS

In patients selected by clinical indicators and duplex ultrasound, reaching a translesional systolic gradient ≤10 mmHg or reduced by at least 80% after angioplasty, promotes a high success rate for PTRA in hypertension due to FMD RAS.

Pathophysiology of Vascular Stenosis and Remodeling in Moyamoya Disease

Moyamoya disease (MMD) and moyamoya syndrome (MMS) are progressive vascular pathologies unique to the cerebrovasculature that are important causes of stroke in both children and adults. The natural history of MMD is characterized by primary progressive stenosis of the supraclinoid internal carotid artery, followed by the formation of fragile collateral vascular networks. In MMS, stenosis and collateralization occur in patients with an associated disease or condition. The pathological features of the stenosis associated with MMD include neointimal hyperplasia, disruption of the internal elastic lamina, and medial attenuation, which ultimately lead to progressive decreases in both luminal and external arterial diameter. Several molecular pathways have been implicated in the pathophysiology of stenosis in MMD with functions in cellular proliferation and migration, extracellular matrix remodeling, apoptosis, and vascular inflammation. Importantly, several of these molecular pathways overlap with those known to contribute to diseases of systemic arterial stenosis, such as atherosclerosis and fibromuscular dysplasia (FMD). Despite these possible shared mechanisms of stenosis, the contrast of MMD with other stenotic pathologies highlights the central questions underlying its pathogenesis. These questions include why the stenosis that is associated with MMD occurs in such a specific and limited anatomic location and what process initiates this stenosis. Further investigation of these questions is critical to developing an understanding of MMD that may lead to disease-modifying medical therapies. This review may be of interest to scientists, neurosurgeons, and neurologists involved in both moyamoya research and treatment and provides a review of pathophysiologic processes relevant to diseases of arterial stenosis on a broader scale.

The Renal Vasculature: What the Radiologist Needs to Know

The physiologic role of the kidneys is dependent on the normal structure and functioning of the renal vasculature. Knowledge and understanding of the embryologic basis of the renal vasculature are necessary for the radiologist. Common anatomic variants involving the renal artery (supernumerary arteries and prehilar branching) and renal vein (supernumerary veins, delayed venous confluence, retroaortic or circumaortic vein) may affect procedures like renal transplantation, percutaneous biopsy, and aortic aneurysm repair. Venous compression syndromes (anterior and posterior nutcracker syndrome) can be symptomatic and can be diagnosed with a combination of radiologic features. Renal artery stenosis is commonly atherosclerotic and is diagnosed with Doppler US, CT angiography, or MR angiography. Fibromuscular dysplasia, the second most common cause of renal artery narrowing, has a characteristic string-of-beads appearance resulting from multifocal stenoses and dilatations. Manifestations of renal vasculitis differ depending on whether the affected vessels are large, medium, or small. Renal vascular injury is graded according to the American Association for the Surgery of Trauma (AAST) renal injury scale, which defines vascular injury and active bleeding in renal injuries. Both renal arteries and veins are affected by primary neoplasms or secondarily by neoplasms from adjacent structures. Differentiation between bland thrombus and tumor thrombus and the extent of involvement dictate management in malignancies, especially renal cell carcinoma. Aneurysms, pseudoaneurysms, arteriovenous malformations, and arteriovenous fistulas can affect renal vessels and can be diagnosed with specific imaging features. The radiologist has a critical role in identification of specific imaging characteristics and establishing the diagnosis in the varied pathologic conditions affecting the renal vasculature, which is critical for directing management. Thus, the renal vasculature should be an integral part of radiologists' checklist. ^©RSNA, 2021.

Arteriopathy in pediatric stroke: an underestimated clinical entity

BACKGROUND

Pediatric arterial ischemic stroke (AIS), which was thought to be a rare disorder, is being increasingly recognized as an important cause of neurological morbidity, thanks to new advances in neuroimaging.

OBJECTIVE

The aim of this study was to review the main etiologies of stroke due to arteriopathy in children.

METHODS

Using a series of cases from our institution, we addressed its epidemiological aspects, physiopathology, imaging findings from CT, MR angiography, MR conventional sequences and MR DWI, and nuclear medicine findings.

RESULTS

Through discussion of the most recent classification for childhood AIS (Childhood AIS Standardized Classification and Diagnostic Evaluation, CASCADE), we propose a modified classification based on the anatomical site of disease, which includes vasculitis, varicella, arterial dissection, moyamoya, fibromuscular dysplasia, Takayasu's arteritis and genetic causes (such as ACTA-2 mutation, PHACE syndrome and ADA-2 deficiency). We have detailed each of these separately. Conclusions: Prompt recognition of AIS and thorough investigation for potential risk factors are crucial for a better outcome. In this scenario, neurovascular imaging plays an important role in diagnosing AIS and identifying children at high risk of recurrent stroke.

Symptomatic internal carotid artery dissection and kinking in a patient with fibromuscular dysplasia

Isolated dissection of the internal carotid artery (ICA) is rare in young patients and is a cause for strong suspicion of fibromuscular dysplasia (FMD), especially when associated with artery elongation and tortuosity. The natural history of cerebrovascular FMD is unknown and management of symptomatic patients can be challenging. We report the case of a 44-year-old female patient with a history of transient ischemic attack in the absence of cardiovascular risk factors, associated with an isolated left ICA dissection and kinking. Carotid duplex ultrasound confirmed the diagnosis of dissection and demonstrated severe stenosis of the left ICA. The patient underwent surgical repair and histopathological evaluation confirmed the diagnosis of FMD with dissection. An autogenous great saphenous vein bypass was performed and the patient had an uneventful recovery. Cervical carotid artery dissection can be related to underlying arterial pathologies such as FMD, and the presence of ICA tortuosity highlights certain peculiarities for optimal management, which might be surgical.

Ex-Vivo Repair of Complex Hilar Renal Artery Aneurysms and Auto-Transplantation of Solitary Kidney

Renal artery aneurysms (RAA) are rare and challenging to repair. We present a case of a 48-year-old female with solitary right kidney who had complex aneurysms near the renal hilum. CT angiogram showed fibromuscular dysplasia (FMD) features of the renal artery and 2 saccular aneurysms measuring 2.3 cm and 1 cm. An additional small lower pole renal artery added to the complexity of the case. Ex-vivo aneurysm repair was performed after the kidney was removed and flushed with preservation solution. This was followed by auto-transplantation to the right external iliac vessels. The patient did well postoperatively without need for dialysis with serum creatinine returning to normal 5 weeks after.

Hypertension and childhood stroke

Cerebrovascular disease (stroke) is one of the ten leading causes of death in children and adolescents. Multiple etiologies, from arteriopathies to prothrombic states, can cause stroke in youth. In adult stroke, hypertension has been shown to be the single most important modifiable risk factor. Although hypertension has not been strongly identified as a risk factor in childhood stroke to date, there is preliminary evidence that suggests that hypertension may also be associated with stroke in children. In this review, we summarize the literature that may link hypertension to stroke in the young. We have identified a series of barriers and limitations in the fields of pediatric hypertension and pediatric neurology that might explain why hypertension has been overlooked in childhood stroke. We suggest that hypertension may be a relevant risk factor that, alone or in combination with other multiple factors, contributes to the development of stroke in children. Currently, there are no consensus guidelines for the management of post-stroke hypertension in children. Thus, we recommend that blood pressure be assessed carefully in every child presenting with acute stroke in order to better understand the effects of hypertension in the development and the outcome of childhood stroke. We suggest a treatment algorithm to help practitioners manage hypertension after a stroke.

Fibromuscular dysplasia: A comprehensive review on evaluation and management and role for multidisciplinary comprehensive care and patient input model

Fibromuscular dysplasia is a nonatherosclerotic, under-recognized disorder primarily seen in middle-aged women. It can lead to several complications, such as hypertension, headaches, dissections, aneurysms, myocardial infarctions, and cerebrovascular accidents, to name a few. This article provides a comprehensive review of current literature on epidemiology, etiology, diagnosis, treatment, and long-term surveillance and fibromuscular dysplasia management. In addition, it renders the role of education and prevention for patients living with this condition and family screening. Lastly, it emphasizes the importance of a comprehensive multidisciplinary care model and patient input, given the complexity of this disease and its systemic presence and protean manifestations.

[Treatment of renal artery stenosis in the year 2021]

Severe arteriosclerotic stenosis of the renal artery with at least 60-70% narrowing of the lumen can lead to various diseases: in the case of unilateral stenosis it can lead to renovascular hypertension, in the case of bilateral narrowing (or in a stenotic solitary kidney) also to an often progressive renal insufficiency (ischemic kidney disease) and/or to acute pulmonary edema (pulmonary flash edema). Renal artery stenosis may be treated by revascularization using either percutaneous (balloon angioplasty with or without stenting) or less commonly open surgical procedures, both with excellent primary patency rates of over 90%; however, randomized trials of catheter-based interventions have failed to demonstrate a longer term benefit with respect to blood pressure control and renal function as well as improved overall survival over optimal medicinal management alone. Due to improved clinical outcomes interventional revascularization is justified in cases with critical stenoses and clinical sequelae, such as pulmonary flash edema and progressive renal failure. Careful patient selection is essential to maximize a potential clinical benefit.

Cervical Carotid Artery Dolichoectasia as a Marker of Increased Vascular Risk

Cervical carotid artery (cCA) dolichoectasia (DE) is characterized by elongation, tortuosity, and/or dilatation. The prevalence of cCA DE has been reported 13-31% in population-based and 14-58% in hospital-based studies. The exact mechanisms of this aberrant arterial remodeling are unknown. Although atherosclerosis has often been implicated, the evidence has conflicting results that would support atherosclerosis as the underlying pathology. Actually, other nonatherosclerotic mechanisms related to connective tissue remodeling may play a role. Such mechanism is supported by epidemiological evidence that cCA DE is associated with carotid dissections. Similarly, cCA DE has been associated with vascular risk factors, but inconsistently. Fewer studies have evaluated the risk of vascular events in people with cCA DE. Cross-sectionally, cCA DE is associated with cerebrovascular disease, including white matter hyperintensities, lacunar stroke, and stroke overall. The often-conflicting results may in part be due to the heterogeneity of the population studies and variable definitions used. Preferential use of objective measure of cCA DE, such as carotid length, is advisable, and may help comparing result among different studies. Prospectively, people with cCA DE have a higher risk of vascular events, although it is uncertain if the risk of stroke is also higher in this population. In the absence of alternative stroke etiologies, stroke patients with cCA DE should be considered to have had a cryptogenic stroke and treated with daily antiplatelet therapy. Further population-based studies are needed to clarify whether specific therapies may be implement to reduce the risk of events among people with cCA DE.

Imaging of Non-atherosclerotic Vasculopathies

Non-atherosclerotic vasculopathies (NAVs) may present with various neurological symptoms ranging from headache, stroke, visual symptoms, and various types of intracranial hemorrhage. NAVs result from different etiologies which include collagenopathies, immunological, hematological, and infection mechanisms, and other rarer unidentifiable or idiopathic causes. NAV etiologies account for about 10–15% and 20–25% of adult and pediatric stroke cases, respectively, and therefore, diagnosing the underlying cause of NAV becomes clinically very important. Clinical diagnosis of NAV is challenging because the clinical presentation is very non-specific and overlapping with various other central nervous system disorders. Before the advent of non-invasive techniques, making a diagnosis of non-atherosclerotic vasculopathy as a cause of the stroke was very challenging. Today with newer techniques such as high-resolution magnetic resonance (MR), MR and computed tomography perfusion, and angiogram, there are number of pointers which can give us a lead about the non-atherosclerotic causes. Imaging may provide the first lead to the clinician regarding the diagnosis or possible differential diagnosis so that the targeted and focused biomarkers (blood, cerebrospinal fluid, or/and in some cases biopsies) may be obtained to clinch the diagnoses. The purpose of the article is to enumerate the causes, clinical features, and illustrate the imaging findings of the various non-atherosclerotic vasculopathic disorders and discuss “pearls” to their diagnosis. In this article, we have also discussed the latest advances in vascular imaging and elaborated on few uncommon non-atherosclerotic vasculopathies. These are very relevant clinically in the day-to-day practice for the radiologist, neurologist, and the neurointerventionalist.

A case of endovascular therapy for treating idiopathic arterial deteriorations of unknown etiology

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A 50-year-old patient presented with multiple idiopathic arterial deteriorations.

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He had a renal artery tear and a pseudoaneurysm of the left internal iliac artery.

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Previous direct intervention failed and we suspected vascular fragility.

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The two lesions were treated by simultaneously placing endografts.

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Endovascular treatment is a desirable option in the case of vascular fragility.

Introduction

Peripheral artery pseudoaneurysm as a consequence of arterial deterioration is relatively rare in young populations, who typically lack an atherosclerotic background. Such pseudoaneurysms are known to pose a risk of rupture, which is correlated with high mortality and morbidity rates. Pseudoaneurysms are more prone to rupture than true aneurysms are, as their vessel walls tear more easily. We present the case of a 50-year-old patient who had multiple arterial deteriorations.

Case presentation

The patient experienced backache, and computed tomography revealed a tear of the right renal artery, and a pseudoaneurysm of the left internal iliac artery. He had a history of graft replacement for the right superficial artery pseudoaneurysm, which had been occluded. Although various tests were performed for differential diagnosis, the etiology was unidentified. Considering the suspected vascular fragility and failure of previous direct intervention, these 2 lesions were treated by placing endografts simultaneously.

Discussion

We investigated various diseases causing vascular fragility in the reported case, such as vascular Behçet disease, vascular Ehlers-Danlos syndrome, fibromuscular dysplasia, and segmental arterial mediolysis. However, these were all excluded and the etiology remains unclear. Progress in endovascular techniques enables the use of minimally invasive treatment in patients with vascular fragility.

Conclusion

When vascular fragility may exist, endovascular treatment is a desirable option, as it can be performed repetitively and is less invasive.

Spontaneous Rupture of Mesenteric Vasculature Associated with Fibromuscular Dysplasia in a 28-Year-Old Male

Spontaneous rupture of mesenteric vasculature associated with fibromuscular dysplasia is an unreported phenomenon. We describe a case in a 28-year-old male with a history of chronic abdominal pain who presented to our facility in hemorrhagic shock secondary to a ruptured transverse mesocolon middle colic aneurysm status postemergent transverse colectomy. He was found to have chronic vertebral, renovisceral, and iliac aneurysms as well as acute superior and inferior mesenteric artery dissection and chronic bilateral vertebral artery dissections. He subsequently developed disseminated intravascular coagulopathy, resulting in saddle pulmonary embolus as well as right renal artery and splenic artery thrombosis. Ultimately, the patient expired.

Spontaneous coronary artery dissection, a commonly overlooked etiology of acute coronary syndrome

Spontaneous coronary artery dissection (SCAD) is a type of non-atherosclerotic coronary artery disease, initially thought to be uncommon but is now being increasingly recognized as a cause of acute coronary syndrome in females. The exact incidence of this remains unknown and most of these cases undergo emergent percutaneous intervention (PCI) due to concern for acute coronary syndrome (ACS). Prior studies have shown that PCI can be detrimental in these cases. It is important to recognize the possibility of SCAD in young female patients so that potentially harmful interventions, such as starting these patients immediately on heparin, use of thrombolytic therapy, and emergent PCI that can lead to worse outcomes, are avoided.

The carotid plaque as paradigmatic case of site-specific acceleration of aging process: The microRNAs and the inflammaging contribution

Atherosclerosis is considered a chronic inflammatory disease of arteries associated with the aging process. Many risk factors have been identified and they are mainly related to life-styles, gene-environment interactions and socioeconomic status. Carotid and coronary artery diseases are the two major atherosclerotic conditions, being the primary cause of stroke and heart attack, respectively. Nevertheless, carotid plaque assumes particular aspects not only for the specific molecular mechanisms, but also for the types of atheroma which may be associated with a better or a worst prognosis. The identification of circulating blood biomarkers able to distinguish carotid plaque types (stable or vulnerable) is a crucial step for the improvement of adequate therapeutic approaches avoiding or delaying endarterectomy in the oldest old individuals (> 80 years), a population predicted to growth in the next years. The review highlights the most recent knowledge on carotid plaque molecular mechanisms, focusing on microRNAs (miRs), as a site-specific accelerated aging within the conceptual framework of Geroscience for new affordable therapies.

Post-traumatic aneurysmal rupture involving the circle of Willis affected by fibromuscular dysplasia. A case report and systematic review

The fatal rupture of a saccular aneurysm at the junction between the left anterior cerebral artery and anterior communicating artery affected by fibromuscular dysplasia (FMD) is a rare condition. Here is reported the case of a subject involved in a road traffic accident a few minutes before the death, which opened the debate on the real cause of death in a forensic setting. By autopsy, the examination of the brain revealed subarachnoid haemorrhage with flooding of the ventricles due to the breached saccular aneurysm of the junction between the left anterior cerebral artery and anterior communicating artery, in FMD mainly affecting the circle of Willis arteries. A spontaneous aneurysmal rupture was excluded on the basis of probabilistic analysis, in the presence of alternative hypotheses that could explain the facts. The passenger's delayed loss of consciousness may be explained as much by a hypertension-linked rupture of the aneurysm triggered by the emotional stress experienced, as by the traumatic shaking/impact of the aneurysm against the bony skull structures, in a subject predisposed to aneurysm frailty due to FMD. Overall, the concausal role of both the road traffic accident, typified by high kinetic energy, and the presence of a pre-existing aneurysmatic weakness due to FMD is fully recognized. The identification of anatomical variants, jointly with uncommon diseases at the examination of the brain base arteries in any case of isolated basal subarachnoid haemorrhage, may avoid wrong legal consequences even when the cause of death seems to be obviously of simple traumatic origin.

When and How Should We Revascularize Patients With Atherosclerotic Renal Artery Stenosis?

Atherosclerotic renal artery stenosis is the leading cause of secondary hypertension and may lead to resistant (refractory) hypertension, progressive decline in renal function, and cardiac destabilization syndromes (pulmonary edema, recurrent heart failure, or acute coronary syndromes) despite guideline-directed medical therapy. Although randomized controlled trials comparing medical therapy with medical therapy and renal artery stenting have failed to show a benefit for renal artery stenting, according to comparative effectiveness reviews by the Agency for Healthcare Research and Quality, the trials may not have enrolled patients with the most severe atherosclerotic renal artery stenosis, who would be more likely to benefit from renal stenting. Because of limitations of conventional angiography, it is critical that the hemodynamic severity of moderately severe (50% to 70%) atherosclerotic renal artery stenosis lesions be confirmed on hemodynamic measurement. The authors review techniques to optimize patient selection, to minimize procedural complications, and to facilitate durable patency of renal stenting. The authors also review the current American College of Cardiology and American Heart Association guidelines and the Society for Cardiovascular Angiography and Interventions appropriate use criteria as they relate to renal stenting.