Isolated spontaneous dissection of the renal artery

From Fibromuscular Dysplasia to Arterial Dissection and Back

Fibromuscular dysplasia (FMD) is an idiopathic and systemic non-inflammatory and non-atherosclerotic arterial disease. Fifteen to 25% of patients with FMD present with arterial dissection in at least one arterial bed. Conversely, a substantial number of patients with renal, carotid, and visceral dissection have underlying FMD. Also, while few patients with FMD develop coronary artery dissection, lesions suggestive of multifocal FMD have been reported in 30-80% of patients with spontaneous coronary artery dissection (SCAD), and the relation between these two entities remains controversial. The frequent association of FMD with arterial dissection, both in coronary and extra-coronary arteries raises a number of practical and theoretical questions: (i) Are FMD and arterial dissections two different facets of the same disease or distinct though related entities? (ii) Is SCAD just a manifestation of coronary FMD or a different disease? (iii) What is the risk and which are predictive factors of developing arterial dissection in a patient with FMD? (iv) What proportion of patients who experienced an arterial dissection have underlying FMD, and does this finding influence the risk of subsequent arterial complications? In this review we will address these different questions using fragmentary, mostly cross-sectional evidence derived from large registries and studies from Europe and the United States, as well as arguments derived from demographics, clinical presentation, imaging, and when available histology and genetics. From there we will derive practical consequences for nosology, screening and follow-up.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.

Renal Outcome and New-Onset Renal and Extrarenal Dissections in Patients With Nontrauma Renal Artery Dissection Associated With Renal Infarction

[Figure: see text].

Spontaneous visceral artery dissections in otherwise normal arteries: Clinical features, management, and outcomes compared with fibromuscular dysplasia

OBJECTIVE

Visceral artery dissection with otherwise normal-appearing arteries (VADNA), diagnosed on imaging and suggestive of segmental arterial mediolysis, is a poorly understood disease entity. Study objectives were to define the clinical features, management, and outcomes of patients with VADNA compared with patients with fibromuscular dysplasia (FMD).

METHODS

In this single-center retrospective cohort study, consecutive patients with a diagnosis of VADNA or FMD evaluated in the Mayo Clinic Gonda Vascular Center (January 1, 2000-April 1, 2017) were identified. Patient demographics, symptom presentation, management, composite adverse arterial events (recurrent arterial dissection, stroke or transient ischemic attack, myocardial infarction, mesenteric or renal infarction, or need for revascularization), and overall survival were compared between VADNA and FMD patients.

RESULTS

There were 103 VADNA patients (age [mean ± standard deviation], 51.7 ± 11.0 years; 27.9% female) and 248 FMD controls (49.8 ± 8.9 years; 81.8% female) identified. The most common symptom for VADNA patients was abdominal or flank pain (80.6%). For FMD, chest pain, headache, and dizziness were more frequent presenting complaints. The median follow-up was longer for VADNA patients (42 months; interquartile range, 9-76 months) compared with FMD patients (19 months; interquartile range, 0.6-52 months; P < .001). During this time interval, there were twofold more composite arterial events in the VADNA group compared with the FMD group (17% vs 8.1%; P = .01). This difference was primarily driven by recurrent dissections. All-cause mortality was low and similar for both groups (3.8% vs 0.4%; P = .10).

CONCLUSIONS

VADNA patients carry a higher risk of recurrent arterial events compared with those with FMD. This difference was primarily driven by recurrent dissections.

The Approach to the Patient with Hematuria

Hematuria is common; whether gross or microscopic, it is incumbent on emergency providers to consider life-threatening and benign processes when evaluating these patients. Most workup is driven by a focused history and physical, including laboratory studies and diagnostic imaging. The cause originates in the genitourinary tract and, as long as the patient remains stable, they can be discharged with close outpatient follow-up. The importance of this cannot be stressed enough because hematuria, especially in the elderly, frequently signals the presence of urologic malignancy. In addition, the workup occasionally yields a nongenitourinary tract cause, and these patients often require emergent management.

Renal Artery Stenting Recovered Renal Function after Spontaneous Renal Artery Dissection

Spontaneous renal artery dissection (SRAD) is a rare entity and the management of this disease has not been established. A 54-year-old man presented with severe flank pain, and contrast-enhanced computed tomography images suggested SRAD in his left renal artery. After two weeks of conservative treatment, stents were placed in the renal artery. The pre- and post-procedural renal function was independently assessed by renography. After stenting, his left renal function recovered from the renal failure pattern. Renal artery stenting in an acute phase of SRAD may salvage the renal function, even if it appears to be non-functioning.

Spontaneous Renal Artery Dissection Resulting in Renal Infarction: A Case Report and Review of the Literature

Spontaneous renal artery dissection is a rare disease and an uncommon cause of renal infarction. The patient was a man who presented to the emergency room with sudden-onset right flank pain. Computed tomography revealed right renal infarction; thus, anticoagulation was initiated. Renal angiography revealed luminal narrowing of the segmental artery to the superior pole of right kidney without a dissection flap or false lumen. We stopped anticoagulation due to a lack of evidence of thrombi or luminal narrowing of the dissected vessels. When patients present with acute flank pain, it is important to suspect renal infarction and to perform a correct diagnostic workup, even when the patient shows normal urinalysis results and a normal LDH value.

Spontaneous dissection of the renal artery: case report

Spontaneous renal artery dissection is rare and most cases are considered idiopathic. Previous renal arterial disease may be present in some cases and clinical presentation is often non-specific. Here, the authors present a case of spontaneous renal artery dissection in a 40-year-old male patient with uncontrolled hypertension discovered during investigation of secondary hypertension. Duplex ultrasound initially showed 80% left renal artery stenosis which was shown to be a renal artery dissection during angiography. The patient was successfully managed by percutaneous placement of a renal artery stent.

Clinical Outcomes of Conservative Treatment in Patients with Symptomatic Isolated Spontaneous Renal Artery Dissection and Comparison with Superior Mesenteric Artery Dissection

OBJECTIVES

The aims of this study were to report the clinical outcomes of conservative medical treatment in patients with symptomatic isolated spontaneous renal artery dissection (SRAD) and compare them with those of spontaneous superior mesenteric artery dissection (SSMAD).

METHODS

This was a single centre, observational comparative study between SRAD and SSMAD. Data from a prospective visceral artery dissection registry were analysed retrospectively. Between June 2010 and December 2016, 23 consecutive patients with symptomatic isolated SRAD who initially received conservative medical treatment were included. The primary outcomes were the aggravation of dissection requiring intervention and dissection related mortality. To evaluate the prognosis of symptomatic isolated SRAD, the clinical outcomes of isolated SRAD were compared with those of symptomatic isolated SSMAD (n = 40) during the same study period.

RESULTS

The primary outcome incidence was 39% (9/23) in patients with symptomatic isolated SRAD during the median follow up period of 20 months (range 0-63 months). The dissection related mortality rate was 17% (4/23), and the cause of death in all cases was an abrupt rupture of the dissecting aneurysm with significant true lumen stenosis. None of the patients without aneurysm or with true lumen occlusion had dissection related mortality. During the same study period, compared with the patients with symptomatic isolated SSMAD who initially received conservative medical treatment, the primary outcome incidence (39% vs. 10%, p = .009) and dissection related mortality rate (17% vs. 0%, p = .016) were statistically significantly higher in patients with symptomatic isolated SRAD.

CONCLUSIONS

Although the present analysis involved only a small number of patients, it revealed that symptomatic isolated SRAD with dissection related aneurysm and true lumen stenosis is a potentially life threatening condition and that aggressive surgical or endovascular interventions should be considered in these patients, who are refractory to conservative medical treatment.

Spontaneous renal infarct heralding bowel ischaemia in an adult male: lessons to learn from a rare clinical association

Spontaneous renal artery dissection (SRAD) is a rare entity with less than 200 cases reported in literature. It usually affects middle-aged men and the clinical presentation is non-specific. Many times it is associated with conditions such as hypertension, fibromuscular dysplasia or vasculitides. We report the case of a patient who initially had renal infarct due to SRAD and then progressed to have bowel ischaemia. The renal infarct preceded bowel ischaemia in this patient and to the best of our knowledge this is the first such association reported in literature. Our report emphasises the point that whenever this condition is diagnosed in a patient one should be vigilant for other vascular disorders.

Case Report: 52-Year-Old Male with Right Upper Quadrant Abdominal Pain

Renal artery dissections (RADs) are lesions that disrupt vessels that primarily occur in patients with a known history of hypertension and caused by stenosis or enlargement of the renal artery typically due to underlying connective tissue disorders. However, RADs may occur spontaneously from trauma and no previous history of hypertension. Here, we report a rare case of bilateral isolated spontaneous RADs that characteristically occurs in healthy males. A 52-year-old male presented with left lower quadrant abdominal pain and renal insufficiency. Two years prior, he had experienced a similar episode of pain on the contralateral side, which was due to an infarct of the right kidney. On this admission, a computed tomography angiogram confirmed a new infarct of the left kidney, with dissection of a branch of the renal artery supplying the upper lobe. Work-up for cardiovascular, hematologic, radiographic or connective tissue causes was negative. We postulate that both RADs were potentially associated with the rapid twisting and turning of the abdominal area on a daily basis required for his occupation as an air traffic controller. The patient was treated with a renin angiotensin system inhibitor. After one year, both RADs had significantly improved and his renal function increased by ~23%. Isolated RAD may be associated with consistent or long-term activities that require rapid twisting and turning of the abdominal area. If left untreated, this may result in malignant hypertension, bilateral dissections, or renal ischemia. To avoid misdiagnosis; we provide a comprehensive review of the typical presentation and necessary assessment and management.

Acute renal artery infarction secondary to dysfibrinogenemia

Renal infarction is a rare occurrence accounting for 0.007% of patients seen in the emergency department for renal insufficiency or hypertension. Dysfibrinogenemia is also rare, and the combination of renal artery infarct in the setting of congenital dysfibrinogenemia has not been described in the literature. Our patient, with a remote history of congenital dysfibrinogenemia with no known haemorrhagic or thrombotic complications, presented with acute flank pain and was subsequently diagnosed with an acute renal arterial infarction. He was treated with subcutaneous enoxaparin and then transitioned to lifelong anticoagulation with rivaroxaban therapy.

Spontaneous Renal Artery Dissection as a Cause of Acute Renal Infarction: Clinical and MDCT Findings

The purpose of this study was to assess the incidence of spontaneous renal artery dissection (SRAD) as a cause of acute renal infarction, and to evaluate the clinical and multidetector computed tomography (MDCT) findings of SRAD. From November 2011 to January 2014, 35 patients who were diagnosed with acute renal infarction by MDCT were included. We analyzed the 35 MDCT data sets and medical records retrospectively, and compared clinical and imaging features of SRAD with an embolism, using Fisher's exact test and the Mann-Whitney test. The most common cause of acute renal infarction was an embolism, and SRAD was the second most common cause. SRAD patients had new-onset hypertension more frequently than embolic patients. Embolic patients were found to have increased C-reactive protein (CRP) more often than SRAD patients. Laboratory results, including tests for lactate dehydrogenase (LDH) and blood urea nitrogen (BUN), and the BUN/creatinine ratio (BCR) were significantly higher in embolic patients than SRAD patients. Bilateral renal involvement was detected in embolic patients more often than in SRAD patients. MDCT images of SRAD patients showed the stenosis of the true lumen, due to compression by a thrombosed false lumen. None of SRAD patients progressed to an estimated glomerular filtration rate < 60 mL/min/1.73 m² or to end-stage renal disease during the follow-up period. SRAD is not a rare cause of acute renal infarction, and it has a benign clinical course. It should be considered in a differential diagnosis of acute renal infarction, particularly in patients with new-onset hypertension, unilateral renal involvement, and normal ranges of CRP, LDH, BUN, and BCR.

Renal Infarction Caused by Isolated Spontaneous Renal Artery Intramural Hematoma

BACKGROUND

Acute renal infarction is an uncommon condition resulting from an obstruction or a decrease in renal arterial blood flow. Isolated spontaneous renal artery intramural hematoma is a rare cause of renal infarction.

CASE REPORT

A 46-year-old healthy man presented to our emergency room because of sudden onset of severe right flank pain. An enhanced abdominal computed tomography scan showed a low-attenuated lesion in the lateral portion of the right kidney but no visible thromboembolisms in the main vessels. Computed tomography angiography revealed acute infarction resulting from intramural hematoma of the anterior segmental artery of the right kidney, with distal occlusion.

CONCLUSIONS

The rarity and non-specific clinical presentation of renal infarction often lead to a delayed diagnosis that may result in impaired renal function. Clinical suspicion is important in the early diagnosis, and intramural hematoma of the renal artery should be considered the cause of renal infarction even in healthy patients without predisposing factors.

Isolated Spontaneous Renal Artery Dissection Presented with Flank Pain

Spontaneous renal artery dissection is a rare but important cause of flank pain. We report a case of isolated spontaneous renal artery dissection in 56-year-old man complicated by renal infarction presented with flank pain. Doppler study pointed towards vascular pathology. Computed tomography (CT) angiography was used to make final diagnosis which demonstrated intimal flap in main renal artery with renal infarction.

Spontaneous renal artery dissection with renal infarction

Spontaneous renal artery dissection (SRAD) is a rare entity, which often presents diagnostic difficulties because of its non-specific clinical presentation. We report six cases complicated with renal infarction, occurring in middle-aged male patients without risk factors, illustrating the difficulty and delay for diagnosing SRAD. Ultrasound and Doppler imaging were not sensitive enough to confirm the diagnosis, and contrast-enhanced abdominal computed tomography was used to correct the diagnosis and allow the clinicians to propose appropriate treatment. We conclude that considering the urgency in diagnosing and treating SRAD, contrast enhanced abdominal tomography and/or abdominal magnetic resonance imaging should be proposed as soon as a suspicion of SRAD is evoked by the clinical presentation.

Fibromuscular dysplasia: what the radiologist should know: a pictorial review

Abstract

Fibromuscular dysplasia (FMD) is an idiopathic, segmentary, non-inflammatory and non-atherosclerotic disease that can affect all layers of both small- and medium-calibre arteries. The prevalence of FMD is estimated between 4 and 6 % in the renal arteries and between 0.3 and 3 % in the cervico-encephalic arteries. FMD most frequently affects the renal, carotid and vertebral arteries, but it can theoretically affect any artery. Radiologists play an important role in the diagnosis of FMD, and good knowledge of FMD’s signs will certainly help reduce the delay between the first symptoms and diagnosis. The common string-of-beads aspect is well known, but less common presentations also have to be considered. These less common imaging findings include vascular loops, fusiform vascular ectasia, arterial dissection, aneurysm and subarachnoid haemorrhage. These radiologic presentations should be known by radiologists in order to diagnose possible FMD, particularly when present in young females or when associated with personal or familial hypertension, to reduce the delay between the onset of the first symptom and the final diagnosis. The patients have to be referred to specialised FMD centres for dedicated management.

Teaching Points

• Fibromuscular dysplasia is not a rare disease.

• Radiologists should recognise less common presentations to orient specific management.

• Vascular loops, fusiform vascular ectasia and a “string-of-beads” aspect are typical presentations.

• Arterial dissection, aneurysm and subarachnoid haemorrhage are less typical radiologic presentations.

Renal infarction due to spontaneous dissection of the renal artery: an unusual cause of non-visceral type abdominal pain

A 44-year-old man presented with very severe right upper quadrant pain of sudden onset. This was exacerbated by movement but unaffected by food or defaecation. It was continuous-day and night -but resolved over a 1-week period. The physical examination was normal at presentation, by which time the pain had resolved. His white cell count, alanine transaminase and C reactive protein were elevated but normalised after 10 days. An abdominal CT showed low density lesions in the right kidney consistent with segmental infarcts. CT angiogram showed a dissection of the right renal artery. The patient remained asymptomatic and normotensive when reviewed 1 month later.

Isolated spontaneous renal artery dissection: a case report and review

We report an interesting case of a 65-year-old gentleman who presented with hypertensive emergency and was found to have an isolated spontaneous dissection of the right renal artery. The dissection was stented via endovascular approach and resulted in marked improvement in blood pressure. Spontaneous renal artery dissection is a difficult condition to diagnose and treat, unless suspected early enough during the course of treatment. Endovascular intervention is the treatment of choice, as failure of conservative treatment may have long lasting clinical implications relating to decreased renal perfusion. Surgical intervention can be associated with high rate of complications.

Evaluation of characteristics, associations and clinical course of isolated spontaneous renal artery dissection

BACKGROUND

Spontaneous renal artery dissection (SRAD) is a rare entity of unknown etiology. We aimed to study the clinical course and outcomes and compare the characteristics of patients with SRAD with those of the general population.

METHODS

All cases of isolated renal artery dissection diagnosed at the University of Michigan Hospitals between January 2000 and July 2012 were identified by the ICD-9 code. Cases were matched by age, gender and race with individuals from the 2009-2010 National Health and Nutrition Examination Survey (NHANES). Characteristics and awareness of comorbid conditions were compared. Information about the clinical course after diagnosis was retrieved from the case group to ascertain their outcomes.

RESULTS

Overall, 17 patients with SRAD with a mean age of 38.6 years (SD = 8.3) were identified. Eleven patients were male and 14 were white. The most common presenting symptom was excruciating sudden-onset flank pain ipsilateral to the site of dissection. Fibromuscular dysplasia, Ehlers-Danlos and polyarteritis nodosa were present in 4, 4 and 1 patients, respectively. After adjusting in a multivariable model, the case group was more likely to report history of hypertension, cancer and connective tissue disorders (P < 0.001), and less likely to have obesity (BMI ≥30 kg/m(2)) compared with the general population. Supportive medical treatment, endovascular intervention and surgery were required in 8, 5 and 4 cases, respectively. After discharge from the hospital, hypertension was adequately controlled in all the patients but one.

CONCLUSION

SRAD may be part of a syndrome having multi-organ involvement. With appropriate medical or surgical management, long-term clinical outcome appears favorable.

Management of isolated non-traumatic renal artery dissection: report of four cases

BACKGROUND

Isolated non-traumatic renal artery dissection (RAD) is a rare disorder with uncertain natural history. The management may be surgical reconstruction, endovascular repair, or conservative medical treatment, yet no official consensus had been established.

PURPOSE

To report the management of four cases of isolated non-traumatic RAD, emphasizing the beneficial role of conservative medical treatment.

MATERIAL AND METHODS

From the year 2000 till 2011, four male patients with mean age of 42.5 years (range 34-48 years) presented with isolated non-traumatic RAD and were initially treated with medical therapy. Transcatheter in situ thrombolysis was performed in a case with thrombotic occlusion.

RESULTS

Isolated non-traumatic RAD in four patients involving at least seven branches progressed to thrombotic occlusion in two branches, luminal narrowing in five, dual lumens in two, and aneurysmal dilatation in three. Medical treatment was efficacious in three patients, who showed persistent preserved renal function, controlled blood pressure, and favorable arterial remodeling. After failure of medical therapy, the fourth patient was referred to surgery. Thrombolysis was successful to dissolute an occluding thrombotic dissection.

CONCLUSION

Conservative therapy is safe and effective when the renal artery is patent and blood pressure is controlled: we propose it as the first line of treatment, reserving interventional management for refractory cases.

Bilateral spontaneous renal artery dissection

Spontaneous renal artery dissection is a rare condition that precedes renal infarction. We describe a 48-year-old, normotensive healthy woman presenting with left flank pain of sudden onset. Enhanced abdominal computed tomography demonstrated a dissecting intimal flap of the left renal artery complicating renal infarction. Doppler ultrasonography, selective angiography, and intravascular ultrasound revealed a dissecting intimal flap, with a large false lumen and narrow true lumen, of the renal artery bilaterally. Conservative management was undertaken with anticoagulant and analgesic therapy, and the patient was discharged after an uneventful clinical course.

An exceedingly rare cause of secondary hypertension: bilateral renal artery dissection possibly secondary to extracorporeal shock-wave lithotripsy (ESWL)

Extracorporeal shock-wave lithotripsy (ESWL) is an effective and relatively non-invasive treatment modality for ureteral or renal calculi. Although it has been accepted as a safe procedure, minor and major complications have been reported after ESWL. Spontaneous renal artery dissection (SRAD) is a rare and usually misdiagnosed condition because of non-specific presentation of the patients. Depending on the severity of the extent of the dissection non-operative or surgical treatment modalities could be performed. We represent a patient with complaints of bilateral flank pain, hematuria and hypertensive urgency who was diagnosed as having bilateral SRAD possibly secondary to ESWL and chronic hypertension.

Spontaneous renal artery dissection: long-term outcomes after endovascular stent placement

PURPOSE

To report long-term clinical and morphologic results after stent placement for spontaneous renal artery dissection (SRAD).

MATERIALS AND METHODS

Between 1991 and 2006, 16 consecutive patients (13 men; mean age, 42 y +/- 12) presented with SRAD in 17 arteries. All patients had uncontrolled hypertension at the time of presentation. Nine patients had lower back pain, 10 had progressive renal insufficiency, and three had both. All patients underwent renal angiography and stent implantation. They were followed up clinically and with renal imaging.

RESULTS

Baseline blood pressure and plasma creatinine levels were 176/107 mm Hg and 142 micromol/L, respectively. Successful renal artery recanalization and stent implantation were achieved in all patients. After a mean follow-up of 8.6 years +/- 3.4, mean blood pressure was 118/78 mm Hg, with Seven patients were taking no antihypertensive medication, with five and four patients taking single or double antihypertensive agents, respectively. The most recent follow-up showed that plasma creatinine levels were normal, and imaging of the renal arteries showed no sign of restenosis or occlusion in all patients.

CONCLUSIONS

Stent implantation for symptomatic SRAD is an effective treatment in the long term and represents a safe alternative to surgery.

Renal infarction caused by spontaneous renal artery dissection: treatment with catheter-directed thrombolysis and stenting

Spontaneous renal artery dissection (SRAD) is rare and presents a diagnostic and therapeutic challenge. We report a case of a 36-year-old man who had an SRAD-complicated renal infarction. The patient experienced severe unilateral flank pain. Enhanced abdominal computed axial tomography scan showed renal infarction, and urinalysis showed no hematuria. Selective renal angiography was essential to evaluate the extent of dissection and suitability for repair. The patient was treated with catheter-directed thrombolysis and frenal artery stenting.

Renal Artery Dissection following Marathon Running

A 38-year-old, previously healthy man presented with flank pain after competing in a marathon. Initial laboratory tests and urinalysis were essentially normal. Both contrast enhanced—computed tomography and magnetic resonance angiography showed an infarcted region of the left lower kidney without renal artery dissection. Thromboembolism was suspected, but further testing was negative. The diagnosis of renal artery dissection was established by angiogram, showing dissection of the segmental branch. The patient remained normotensive, maintained normal renal function, and had resolution of pain symptoms prior to discharge. On the basis of our experience and review of the literature, renal artery dissection occurs in otherwise healthy men and often goes undiagnosed. The management strategy tends to be conservative unless the patient develops progressive decline in renal function or worsening hypertension, with an excellent prognosis. This case also shows the importance of discussing the pros and cons of extreme physical exertion with all patients.

Fibromuscular dysplasia

Fibromuscular dysplasia (FMD), formerly called fibromuscular fibroplasia, is a group of nonatherosclerotic, noninflammatory arterial diseases that most commonly involve the renal and carotid arteries. The prevalence of symptomatic renal artery FMD is about 4/1000 and the prevalence of cervicocranial FMD is probably half that. Histological classification discriminates three main subtypes, intimal, medial and perimedial, which may be associated in a single patient. Angiographic classification includes the multifocal type, with multiple stenoses and the 'string-of-beads' appearance that is related to medial FMD, and tubular and focal types, which are not clearly related to specific histological lesions. Renovascular hypertension is the most common manifestation of renal artery FMD. Multifocal stenoses with the 'string-of-beads' appearance are observed at angiography in more than 80% of cases, mostly in women aged between 30 and 50 years; they generally involve the middle and distal two-thirds of the main renal artery and in some case also renal artery branches. Cervicocranial FMD can be complicated by dissection with headache, Horner's syndrome or stroke, or can be associated with intracerebral aneurysms with a risk of subarachnoid or intracerebral hemorrhage. The etiology of FMD is unknown, although various hormonal and mechanical factors have been suggested. Subclinical lesions are found at arterial sites distant from the stenotic arteries, and this suggests that FMD is a systemic arterial disease. It appears to be familial in 10% of cases. Noninvasive diagnostic tests include, in increasing order of accuracy, ultrasonography, magnetic resonance angiography and computed tomography angiography. The gold standard for diagnosing FMD is catheter angiography, but this invasive procedure is only used for patients in whom it is clinically pertinent to proceed with revascularization during the same procedure. Differential diagnosis include atherosclerotic stenoses and stenoses associated with vascular Ehlers-Danlos and Williams' syndromes, and type 1 neurofibromatosis. Management of cases with renovascular hypertension includes antihypertensive therapy, percutaneous angioplasty of severe stenoses, and reconstructive surgery in cases with complex FMD that extends to segmental arteries. The therapeutic options for securing ruptured intracerebral aneurysms are microvascular neurosurgical clipping and endovascular coiling. Stenosis progression in renal artery FMD is slow and rarely leads to ischemic renal failure.

[Fibromuscular dysplasia]

Fibromuscular dysplasia is an idiopathic, segmental, nonatherosclerotic and noninflammatory disease of the muscle layer of arterial walls that leads to stenosis of small- and medium-sized arteries. Fibromuscular dysplasia preferentially affects young women. Although it can affect every arterial tree, it most often touches the renal and internal carotid arteries. Renal fibromuscular dysplasia can cause hypertension by stenosis of the renal artery, most often seen on angiography as resembling a "pearl necklace". Cerebrovascular fibromuscular dysplasia becomes symptomatic when the arterial stenosis is tight and causes hypoperfusion, embolism, or thrombosis or when arterial dissection or rupture of the associated aneurysm occurs.

Utility of percutaneous treatment in spontaneous renal artery dissection: case report and review of the literature

Spontaneous renal artery dissection (SRAD) is a relatively rare entity that has been described in several case reports and small series in the medical literature. The condition is best diagnosed with angiography, with renal ischemia or infarction a common complication. Conservative medical management, surgical intervention, and percutaneous intervention are all discussed in the current literature. However, there is no consensus on which treatment option provides the best clinical outcome. Percutaneous stent placement has only recently been considered as an option for treatment of SRAD. This case report reviews the course of an otherwise healthy patient with a solitary right kidney who had SRAD complicated by renal infarction and was treated by percutaneous renal artery stent placement. Subsequently, we discuss and review the literature on SRAD treatment.

Spontaneous renal artery dissection: three cases and clinical algorithms

Spontaneous renal artery dissection (SRAD) is rare. Clinical manifestations vary from minimal symptoms to life-threatening hypertension. We analysed three cases from our institution and conducted a literature review in order to design diagnostic and treatment algorithms for SRAD.

Thrombolytic therapy followed by stenting for renal artery dissection secondary to blunt trauma

A 18-year-old man presented at our clinic with pain in the right flank following a motorbike accident. The diagnosis of renal artery dissection followed by thrombosis was made by computed tomography and confirmed by angiography. Successful revascularization was performed by means of repeated transcatheter injection of small doses of thrombolytic agents within the vessel, followed by deployment of a self-expandable stent. There were no complications, and the patient recovered well. Six months after stent placement, a selective renal angiogram showed excellent flow through the stented portion of the artery and normal parenchyma enhancement in the right kidney.

Renal Artery Dissection after Angiographic Evaluation of Lower Extremities

We describe a case of renovascular hypertension that was caused by renal artery dissection after an angiographic evaluation of the lower extremities. Retention of contrast medium in the affected kidney even 1 day after the procedure caused us to suspect renal artery dissection. Magnetic resonance angiography revealed irregular streaks in the lumen of the affected artery, a sign of dissection. Treatment by a transluminal angioplasty with stent insertion improved renal function and reduced systemic blood pressure with normalization of plasma renin activity. In patients whose systemic blood pressure increases suddenly after any conceivable physical traction on the abdominal aorta, evaluation of the renal arteries should be considered. Appropriate endovascular treatment can preserve renal function and reduce systemic blood pressure.

Spontaneous Multiple Arterial Dissections Presenting With Renal Infarction and Subarachnoid Hemorrhage in a Patient Under Treatment for Infertility

A 36-year-old woman developed multiple spontaneous arterial dissections in both renal arteries, the carotid artery, superior mesenteric artery, and vertebral artery, but not the aorta, and she suffered a renal infarction and subarachnoid hemorrhage within a short period of time. She had been undergoing frequent injections of human chorionic gonadotropin and human menopausal gonadotropin, together with oral estrogen therapy, during a 5-year infertility treatment regimen. As she had no other history of any disorder affecting the arterial walls, this therapy is suspected to have caused the multiple arterial deformities. Although cases of isolated arterial dissection are occasionally reported, it is rare for multiple dissections and serious symptoms to occur simultaneously.