Midaortic syndrome in a middle-age female

Description

The midaortic syndrome is a rare condition that mainly affects the abdominal aorta. It is characterised by narrowing the distal thoracic or abdominal aorta and its branches, known as ‘abdominal aortic coarctation’.¹ It can be congenital or acquired postnatally. In congenital coarctation, there is an incomplete fusion of the embryonic dorsal aorta.¹ The male to female ratio is 3:1. The aetiology is unknown. Failure of defence mechanisms during early fetal life lead to infection and can interfere with cell growth and progression of the aorta.² The most common site is inter renal, followed by suprarenal, infrarenal and diffuse.³

The collateral network will be formed from various branches from subclavian, superior mesenteric and axillary arteries connecting to the inferior mesenteric, lumbar, femoral arteries and the superior haemorrhoidal pathways.⁴

The typical presentation is a headache in the occipital region due to uncontrolled hypertension. Other symptoms include dizziness, palpitations, fatigability, epistaxis and blurred vision. The gravity of clinical presentation depends on the grade of aortic stenosis, the extent of branch involvement and collateral formation. The physical examination may reveal cardiac murmurs, continuous and midsystolic abdominal bruits from the collateral vessels. The most common reason for mortality is the cardiovascular complication.⁵ Imaging techniques play a crucial role to evaluate stenosis. Doppler ultrasonography helps in illustrating localised aortic stenosis. Multidetector CT angiography and magnetic resonance angiography have become the primary tools for evaluating patients with suspected aortic abnormalities.

Primary management includes oral antihypertensive to control hypertension. The requirement of intervention primarily depends on the severity of hypertension. Open surgery is considered the primary treatment of tubular aortic narrowing.

Prognosis after uncompromised surgical reconstruction is rewarding in the mid term and long term in patients with congenital aortic coarctation.

We report a case of a 50-year-old middle-aged woman who came to the outpatient department with a 1-month history of vague abdominal pain. Her physical examination, including blood pressure, did not reveal significant findings. The patient had no important medical history or positive family history. Routine investigations were unremarkable. X-ray abdomen and ultrasonography abdomen did not reveal any abnormality. As the complaint persisted for a longer duration without any identifiable aetiology, patient was advised contrast-enhanced CT (CECT) of the whole abdomen for further workup.

CECT abdomen revealed significant stenosis of the infrarenal aorta, causing complete luminal narrowing extending at the L1–L3 vertebral level (length of the involved segment measures approximately 2.7 cm) (figure 1A). Renal arteries on either side arise just before the stenotic segment (figure 1B). Multiple arterial collaterals were identified arising from the proximal part of the aorta. There was large dilated tortuous arterial collateral arising from the proximal superior mesenteric artery and distally connecting to the inferior mesenteric artery forming the arch of Riolan (figures 2A, B and 3). Distal runoff was normally opacified with contrast media. Additionally, we found an accessory renal artery on the left side. The patient was diagnosed with midaortic syndrome and was managed conservatively. Follow-up at regular interval was advised.

Figure 1.

Reformatted images of contrast-enhanced CT (CECT) of abdomen. (A) Sagittal image revealed significant stenosis of the infrarenal aorta causing complete luminal narrowing of the involved segment, at the L1–L3 vertebral level seen as soft tissue density thread like structure without opacification by contrast media (white arrow). Post-stenotic segment of the aorta is opacified with contrast media via large arterial collateral (black arrow). Origin of the superior mesenteric artery is seen normally (asterisk). (B) Maximum intensity projection, coronal images with slice thickness 12 mm depict stenotic infrarenal aortic segment (white arrow). Origin of the renal arteries seen just above the stenotic segment. Accessory renal artery is noted on left side (1 and 2). Large arterial collateral is seen attached to the post-stenotic segment of the aorta (black arrow). Distal run off was normally opacified with contrast media.

Figure 2.

(A) Reformatted images of contrast-enhanced CT of the abdomen, maximum intensity projection, coronal images with slice thickeness 12 mm depict complete stenosis of infrarenal aorta (white arrow) with large arterial collateral connecting to the inferior mesenteric artery distally (black arrow). (B) Volume rendering technique image of aorta shows non-visualisation of the infrarenal aorta causing complete luminal narrowing (white arrow). Large arterial collateral maintaining distal blood supply connecting superior mesenteric artery proximally (asterisk) to the inferior mesenteric artery distally (black arrow) forming ‘arch of Riolan’.

Figure 3.

Arterial phase, volume rendering technique (VRT) image of abdominal aorta and its branches demonstrating origin of coeliac trunk (1), superior mesenteric artery (2) and inferior mesenteric artery (3). Image also demonstrates a large arterial collateral (black star) arising from the proximal superior mesenteric artery (asterisk) and connecting to the inferior mesenteric artery distally, thus forming ‘arch of Riolan’.

Patient’s perspective.

I had severe abdominal pain every alternate day. It was there for a longer time and hampering my routine work. I took medicines for a long time but got no relief. I went to the higher centre and was advised to get ultrasonography and CT scan done based on my long history. CT scan gave some diagnoses related to my abdomen pain. My symptoms improved by conservative management. I was advised to visit the hospital at regular intervals and keep a check on my blood pressure.

Learning points.

• Midaortic syndrome is a rare occurrence, usually affects children and young adults and presents with uncontrollable hypertension due to renal artery involvement. It has to be differentiated from other causes of uncontrollable hypertension, such as fibromuscular dysplasia and vasculitis.

• Infrarenal midaortic syndrome presents with vogue abdominal discomfort without hypertensive symptoms. Prompt treatment and follow-up are required due to progressive involvement of the branches of the aorta, which may cause life-threatening hypertension in later stages.

• CT aortography remains the investigation of choice for the diagnosis of the midaortic syndrome and to evaluate extension of the stenotic segment.

Ethics statements

Patient consent for publication

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