midaortic syndrome ( mas ) is a rare disease characterized by luminal narrowing of the abdominal aorta , and involves stenosis of the major branches in the abdomen . in 1963
, the first paper was published describing the narrowing of the descending aorta as mas , unlike takayasu 's syndrome that involves the aortic arch and leriche syndrome that involves aortic bifurcation1 ) .
clinical manifestations typically include malignant hypertension , claudication , or abdominal angina in adolescents and young adults . in children
, hypertension is an undervalued problem , which can be fatal or lead to a life - threatening emergency if untreated .
hypertension with mas is severe and often unresponsive to several antihypertensive drugs , ultimately requiring surgical intervention . here
, we report a case of a 3-year - old boy presenting with left ventricular hypertrophy , who was diagnosed with idiopathic mas following identification of severely elevated blood pressure ( bp ) .
an echocardiogram showed mild left ventricle ( lv ) hypertrophy , and he was referred to seoul national university children 's hospital for further management .
transthoracic echocardiogram revealed mild lv hypertrophy with increased lv mass index ( 89 g / m or 52 g / m , fig .
even though he did not complain of any symptoms at the time , we administered carvedilol 3.125 mg every 12 hours for lv reverse remodeling . during a routine follow - up echocardiogram 9 months later , we found abnormally increased celiac artery velocity with a diastolic tail ( peak velocity of greater than 4 m / sec , fig .
he was hospitalized for evaluation of renovascular hypertension and bp management at 4 years of age . on admission
the patient 's body weight was 21.2 kg ( > 97th percentile ) and height was 110.1 cm ( > 97th percentile ) .
his bp was high ( 206/113 mmhg in the right arm and 194/104 mmhg in the right leg ) .
a chest x - ray showed no significant cardiomegaly and a 12-lead electrocardiogram revealed lv hypertrophy ( fig .
laboratory findings on admission were as followings : serum blood urea nitrogen , 17.0 mg / dl ; serum creatinine , 0.53 mg / dl ; serum renin activity , 21.0 ng / ml / h ( reference value , < 6.7 ng / ml / hr ) ; and serum aldosterone , 39.4 ng / dl ( reference value , 335 ng / dl ) .
renal artery doppler ultrasonography showed an intermittent tardus parvus spectrogram in both renal arteries with a smaller right kidney ( fig .
3a ) . under the impression of renovascular hypertension , we performed computed tomographic ( ct ) angiography of the abdomen .
the ct angiography revealed severe stenosis at the bilateral renal artery , the ostium of the celiac branch , and the ostium of the superior mesenteric artery with diffuse luminal narrowing of the abdominal aorta into the femoral artery ( fig .
we prescribed labetalol continuous infusion , titrated up to 3 mg / kg / hr and administered concomitant oral antihypertensive medications ( amlodipine 2.5 mg twice a day and atenolol 5 mg twice a day ) to decrease the bp .
percutaneous transluminal renal angioplasty ( ptra ) was planned and abdominal aortogram confirmed diffuse luminal narrowing of the abdominal aorta into the femoral artery ( fig .
ptra was attempted with a 320 mm savvy balloon catheter via the right femoral artery ; however , the effect was unsatisfactory because of the resistance to the balloon dilatation .
he was discharged with combinations of 3 oral antihypertensive drugs ( amlodipine 2.5 mg twice a day and atenolol 12.5 mg once a day and enalapril 2.5 mg twice a day ) . at the time of discharge ,
bp was still high and measured as 134/60 mmhg in the right arm . since three years after first admission , he has been followed up at the outpatient clinic without any complications and is taking 3 combinations of antihypertensive drugs ( amlodipine 5 mg twice a day , atenolol 12.5 mg once a day and enalapril 1.25 mg once a day ) .
we described a 3-year - old boy presenting with lv hypertrophy who was diagnosed with idiopathic mas following identification of severely elevated bp . to the best of our knowledge ,
mas is prone to be referred to as hypoplasia or coarctation of the descending aorta , which presents with symptoms such as headache , claudication , and postprandial abdominal pain .
severe hypertension has been known to be the most common presentation leading to congestive heart failure , renal failure and severe lower extremities claudication7 ) .
previous studies have reported that mas is commonly diagnosed within the first 3 decades89 ) .
recently , the intensive school healthy screening system substantially aids the earlier detection in developed countries , although the patient has had no specific symptoms . moreover
, the widespread use of radiological modalities such as ct or aortography has led to the better recognition of mas .
the etiology of mas is not completely understood , and it can be congenital or acquired . congenital mas is a developmental defect that is caused by both incomplete fusion and overfusion of the paired embryonic dorsal aorta1011 ) .
the most common location of stenosis is the proximal renal artery ( up to 80% ) , and at least 25% of cases may occur in the superior mesenteric artery91112 ) .
acquired mas is caused by takayasu 's arteritis , neurofibromatosis , fibromuscular dysplasia , retroperitoneal fibrosis , mucopolysaccharidosis , and williams syndrome13 ) .
severe complications such as congestive heart failure , cerebrovascular disease , and hypertensive encephalopathy present frequently and may be fatal .
the response to antihypertensive drugs is known to be poor in hypertension with mas and several previous studies have shown vascular surgery to be the best curative therapy14 ) . as experience with ptra grows ,
however , the ptra success rate decreased with mas compared with isolated renal artery stenosis because of the extensive stenotic nature of the aorta and renal branches15 ) , even though ptra is successful in reducing hypertension by using different technical approaches in the arteries from one study3 ) . in conclusion , we report a 3-year - old boy presenting with left ventricular hypertrophy who was diagnosed with congenital mas following the identification of severely elevated bp . clinical suspicion and accurate examination , including bp measurement , would aid early diagnosis of mas and optimal treatment , and are important to prevent the fatal complications from hypertension .
 midaortic syndrome ( mas ) is a rare vascular disease that commonly causes renovascular hypertension . 
 the lumen of the abdominal aorta narrows and the ostia of the branches show stenosis . 
 mas is associated with diminished pulses in the lower extremities compared with the upper extremities , severe hypertension with higher blood pressure in the upper rather than lower extremities , and an abdominal bruit . 
 the clinical symptoms are variable , and recognition in children with hypertension can aid early diagnosis and optimal treatment . 
 hypertension with mas is malignant and often refractory to several antihypertensive drugs . 
 recently , radiologic modalities have been developed and have led to numerous interventional procedures . 
 we describe the case of a 3-year - old boy presenting with left ventricular hypertrophy whose severely elevated blood pressure led to the diagnosis of idiopathic mas . 
 this case highlights the importance of measuring blood pressure and conducting a detailed physical examination to diagnose mas . 
 this is the first reported case of idiopathic mas diagnosed in childhood in korea . 