fibromuscular dysplasia ( fmd ) represents a group of non - atherosclerotic and non - inflammatory arterial diseases that most commonly involve the renal and carotid arteries . they often present with signs and symptoms related to reduced downstream perfusion ( e.g. cerebral ischemia ) . while fmd of the renal arteries is an established cause of secondary hypertension , its association with renal infarction , which often has a subtle presentation , is very rare and less well recognized . here , we report a case of fmd presenting with bilateral renal infarcts as well as severe hypertension , and briefly review the clinical , laboratory and imaging findings of the patient . we also provide an overview of the previous reports to help identify common characteristics that can be used to facilitate the diagnosis . a 53-year - old caucasian man with no major past medical history except for squamous cell carcinoma of the neck presented with sudden onset right loin pain associated with nausea . his physical examination was remarkable for a blood pressure of 194/129 mmhg , regular heart rate of 87 bpm and right lower quadrant abdominal tenderness without any skin lesions . laboratory studies showed a serum creatinine level of 1.20 mg / dl ( 106.08 mol / l ) , mild leukocytosis with wbc of 13 800/mm , hematuria and leukocyturia . computed tomography ( ct ) angiography of the abdomen was performed to further explore the etiology of abdominal pain ; it revealed several wedge - shaped renal infarcts bilaterally ( figure  1 ) as well as multiple short - segment dissections of the middle colic , right renal , left renal and left external iliac arteries . c - reactive protein was elevated at 193.7 mg / l ( reference range : 04.9 mg / l ) . a comprehensive immunologic workup including antinuclear antibody , antineutrophil cytoplasmic antibodies , serum and urine protein electrophoresis as well as serum complement levels was normal . thrombophilia tests including protein c , protein s , anticardiolipin antibody , anti-2 microglobulin antibody and factor v leiden were all negative . 1.ct angiogram of the abdomen reveals bilateral renal infarcts ( arrows ) that are predominant on the right side . ct angiogram of the abdomen reveals bilateral renal infarcts ( arrows ) that are predominant on the right side . in light of imaging evidence of short - segment dissections and downstream ischemia of multiple arteries associated with the lack of any evidence of an ongoing immunologic process , cutaneous lesions or hypercoagulability state , the diagnosis of fmd was made . supportive therapy , including analgesics and intravenous antihypertensive agents that were subsequently switched to oral medicines , was followed by improvement in symptoms and adequate control of blood pressure ; the follow - up ct angiography a few weeks later demonstrated stabilization of the renal lesions . interestingly , a subsequent ct angiography that was performed 8 months later could further identify several clinically silent microaneurysms . the incidence of renal infarction ( ri ) has been estimated to be as low as 0.007% , but it should be noted that it remains undiagnosed in a significant subset of patients . although ri typically presents with flank or abdominal pain , fever , nausea and vomiting , its only presentation can be acute severe hypertension . laboratory studies reveal hematuria in most instances , and the blood levels of lactate dehydrogenase and c - reactive protein are frequently elevated [ 2 , 3 ] . vegetations in infective endocarditis and heart tumors are other potential cardiac sources of emboli , while hypercoagulability , autoimmune disorders , sickle cell disease and aortic interventions comprise the main non - cardiac etiologies . diseases associated with interruption of the renal arterial endothelium such as vasculitis , marfan syndrome and fmd are among less common causes of ri [ 1 , 2 ] . in our patient , once the renal infarcts were identified , cardiac echography was performed to explore a potential cardiac source for emboli . similarly , a comprehensive workup for vasculitis and hypercoagulability that was carried out in search for more common identifiable causes of renal infarct was negative . fmd is a non - inflammatory vascular disease that primarily affects small- and medium - sized arteries . it is most common in the renal and internal carotid arteries , but involvement of almost every arterial bed in the body has been described . the clinical presentation of fmd varies widely from an asymptomatic condition to a multisystem disease depending on the anatomic distribution , extent of vascular involvement and the type of fmd . it is bilateral in 3550% of cases ; nearly half of the patients with bilateral renal arterial fmd will have extra - renal involvement . while various degrees of renal dysfunction are reported in up to 63% of patients , overt renal failure is uncommon in this setting . our case presented with slight elevation of serum creatinine and acute onset of severe hypertension . due to bilateral involvement of the renal arteries , a doppler ultrasound of the carotid arteries renal infarction is seen in only 0.9% of the patients with fmd ; bilateral renal infarction is extremely rare and has so far been reported only in a handful of cases [ 49 ] . interestingly , while fmd as a cause of renal artery stenosis is more common in young females , cases of associated renal infarction seem to have an equal distribution in both genders with a median age of 39 . it is also noteworthy that the majority of the patients whose renal arterial damage due to fmd has been severe enough to result in infarction ( including those with involvement of bilateral renal arteries ) did not present with extra - renal manifestations . this could potentially represent a challenging aspect of the diagnosis of fmd in acute cases . moreover , renal function was reported to be normal or close to normal in most cases , although all patients except for one presented with hypertension . our patient 's serum creatinine that was slightly elevated at the time of admission decreased to 0.9 mg / dl ( 79.5 mmol / l ) at discharge ; after 8 months of follow - up his renal function remained normal . 
 table  1.reported cases of renal infarction complicating fmdcaseage / genderpresenting symptomsblood pressurerenal functionrenal infarctionextra - renal manifestationfmd 44 mright loin pain191/106egfr 71 ml / minunilateral , rightnoneangiographymedicalconnor and mathieson 28 fleft loin pain , vomiting and fever154/80nsunilateral , leftprobable involvement of hepatic arteryangiographymedicalsinnamon et al 34 mbilateral loin pain and fever160/95nsbilateralnoneangiography and md - ctaptasalifu et al . 40 mbilateral flank pain and fever200/103cr 1.6 mg / dl ( 141 mol / l)bilateralnonemra and angiographymedicaldursun et al . 37 mbilateral flank pain and fever160/100cr 3.3 mg / dl ( 292 mol / l)bilateralnonemra and angiographyptabasile et al . 43 mbilateral flank pain150/100cr 1.8 mg / dl ( 159 mol / l)bilateralnonect angiography and sramedicalpresent case53 mright loin pain , nausea194/129cr 1.2 mg / dl ( 106 mol / l)bilateralmultiple arterial involvement in the abdomenct angiographymedicalns , not specified ( mentioned as normal ) ; pta , percutaneous transluminal angioplasty ; mra , magnetic resonance angiography ; md - cta , multi - detector ct angiography ; sra , selective renal arteriography ; egfr , estimated glomerular filtration rate . reported cases of renal infarction complicating fmd ns , not specified ( mentioned as normal ) ; pta , percutaneous transluminal angioplasty ; mra , magnetic resonance angiography ; md - cta , multi - detector ct angiography ; sra , selective renal arteriography ; egfr , estimated glomerular filtration rate . in the past , the gold standard for the diagnosis of renal artery fmd was considered to be digital subtraction angiography ( dsa ) . currently , there are several non - invasive imaging modalities that are available for the diagnosis of fmd ; doppler ultrasound , contrast - enhanced ct scan angiography ( cta ) and magnetic resonance angiography ( mra ) . two retrospective studies have reported a high sensitivity for cta and mra in this setting , which is comparable for the two modalities [ 14 , 15 ] . therefore , cta or mra should be initially considered in the diagnosis of fmd , and dsa be reserved for those cases where the findings of these imaging studies are inconsistent in the presence of high clinical suspicion . in our patient , the diagnosis was made by cta that confirmed the presence of multiple arterial bed involvement characteristic of fmd , including several microaneurysms that were identified on a subsequent ct scan several months later . the main impetus in management of patients with renal fmd is control of hypertension . in most patients , it can be primarily managed medically ; the principles of drug therapy are based on the presence of renal artery stenosis and renal hypoperfusion . in patients with unilateral renovascular fmd , activation of renin  angiotensin  aldosterone system ( raas ) with its downstream effects is considered the primary mechanism of hypertension . in these cases , the contralateral kidney maintains adequate natriuresis , thus avoiding aldosterone - mediated sodium and fluid retention . raas blockade is , therefore , the initial target in unilateral renovascular fmd . in cases of bilateral disease , natriuresis can not occur leading to sodium and volume overload and portending an additive impact on raas - mediated hypertension . raas blockers could lead to significant perturbation in renal hemodynamics in these cases ; close monitoring of renal function is warranted . diuretics can be used as a second - line therapy in unilateral disease and possibly as first line in cases of bilateral disease . our patient 's blood pressure has remained under tight control with an angiotensin - converting enzyme inhibitor as well as a beta blocker . revascularization is reserved for patients with resistant hypertension , poor tolerance or non - compliance with medications , and progressive deterioration in renal function from ischemic nephropathy . percutaneous transluminal angioplasty has largely replaced surgery as the preferred treatment of renal arterial fmd . over the years , the technical success rate of the procedure has approached 100% , and it leads to cure or improvement of hypertension in a high percentage of patients with fmd . the underlying mechanism for the renal infarct in fmd is not entirely clear , evidence is lacking regarding the benefit of anticoagulation for patients with ischemia / infarction secondary to fmd . our patient initially received anticoagulation with heparin due to extensive infarction ; it was subsequently stopped once thromboembolic etiologies were eliminated . this case , coupled with previous reports , illustrates the high variability of the presentation of fmd ranging from asymptomatic disease to extensive infarcts and acute severe symptoms . fmd is a clinical diagnosis that should be considered in those patients presenting with otherwise unexplained renal ischemia or infarction and involvement of multiple arteries , particularly in the context of new - onset or severe hypertension .
while fibromuscular dysplasia ( fmd ) is an established cause of secondary hypertension , its association with renal infarction is less well recognized . 
 we report a middle - aged man who presented with complaints of loin pain and severe hypertension . 
 computed tomography angiography of the abdomen revealed bilateral renal infarction with multiple short - segment arterial dissection compatible with fmd in the absence of systemic vasculitis and other risk factors for thromboembolic events . 
 bilateral renal infarction complicating fmd is extremely rare and has so far been reported only in a handful of cases . 
 physicians encountering cases of otherwise unexplained renal infarction / ischemia need to be aware of this complication .