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.

A Case of Spontaneous Renal Artery Dissection Secondary to Fibromuscular Dysplasia and Treatment by Renal Arterial Stenting / 대한신장학회잡지

Isolated spontaneous renal artery dissection (SRAD) associated with fibromuscular dysplasia (FMD) is a rare condition that can result in renal infarction. Treatment and long-term management of patients with this condition is controversial. We report the case of a patient with SRAD secondary to FMD who was treated by renal arterial stenting. A previous healthy 50-year-old white male presented to the emergency department with acute right flank pain. Blood pressure was 150/90 mmHg and serum creatinine was 1.6 mg/dL. A CT scan of the abdomen showed multifocal right renal infarction. The patient was started on anticoagulant regimen of heparin. Renal angiography showed the dissection of right renal artery and stenosis of mid-segment of right main renal artery and intrarenal branches. We decided to perform percutaneous balloon angioplasty and stenting for the purpose of dilating the stenotic renal artery, preventing recurrence of the disease and controlling hypertension and elevated creatinine. A dissected intimal flap was closed successfully by renal artery stenting and stenotic renal artery was dilated by stenting and balloon angioplasty. Five days after the procedure, he was discharged with warfarin. Three months later, he had normal renal function and blood pressure without antihypertensive medication was mildly elevated at 145/104 mmHg. Conclusively, stent implantation to renal artery dissection can be effective, reliable and feasible and can be an alternative to surgical treatment.

A Case of Spontaneous Renal Artery Dissection Causing Renal Infarction in a Previously Healthy Man / 대한신장학회잡지

Spontaneous renal artery dissection is an uncommon cause of renal infarction. Previous reports of spontaneous renal artery dissection has been associated with hypertension or fibromuscular dysplasia. We report herein the case of a previously healthy, normotensive patient with renal infarction due to spontaneous renal artery dissection who remained normotensive throughout his course without therapy. A previously healthy 31-year-old man with well- documented normotension had a sudden onset of right flank pain and delayed onset of elevation of lactic dehydrogenase, hematuria, and proteinuria. Thin section spiral computerized tomogram shows linear intraluminal filling defect suggesting intimal flap. Angiography shows dissection of main right renal artery. Six months later, he has remained well and normotensive without therapy. To our knowledge, this is the first case of spontaneous renal artery dissection in normotensive patients in Korea.

A Case of Spontaneous Renal Artery Dissection with Renal Infarction in a Healthy Man Without Hypertension / 대한신장학회잡지

It is usually known that arterial dissection is associated with malignant hypertension, severe atherosclerosis or trauma. Marfan syndrome or Ehlers- Danlos syndrome may also be rare causes. However, as in this case, spontaneous arterial dissection without aortic dissection in normotensive men is rarely reported. A 39-year-old man presented with acute onset right flank pain with microscopic hematuria. Physical examination was unremarkable and his blood pressure was normal. Clinical impression was urolithiasis because he experienced two episodes of urolithiasis previously. IVP was not completed due to adverse reaction during study. Right renal infarction was diagnosed by contrast-enhanced computed tomography. To search for possible cardiac embolic disease, the patient underwent surface echocardiography, which was normal and a detailed evaluation for a thrombotic tendency was unremarkable. A renal arteriogram showed dissection of the main right renal artery with extension to renal artery branches and a wedge-shape perfusion defect in the distal part of the occluded artery. He received aorto-renal bypass surgery using his great saphenous vein. The patient developed hypertension 3 months later. To summary, we report a case of spontaneous renal artery dissection with renal infarction in a healthy man without hypertension.