Mediacalcosis (mediacalcinosis)

Mediacalcosis or mediacalcinosis is a progressive calcifying sclerosis of the arterial tunica media, preferentially affecting medium-caliber arteries.

Clinically, it is characterized by reduced or absent perception of peripheral pulses (arterial rigidity, "incompressible arteries"). This clinical feature is shared by obliterative arteriopathy of the lower limbs (AOMI), making it a differential diagnosis.

Etiologies

This condition is still the subject of much debate, including as to its origin. Some consider it a simple manifestation of senescence. Others consider disorders of phospho-calcium metabolism (including their causes, such as chronic renal failure), diabetes or arterial hypertension as etiological or favouring factors...

Clinical features

Mediacalcosis is characterized by a decrease or abolition of peripheral pulses on clinical examination.

Its possible pathological implications are controversial. Some studies suggest an increased risk of coronary events and heart failure (reduced arterial compliance increases the risk of left ventricular hypertrophy and ultimately coronary perfusion)... However, this has never been significantly demonstrated.

Complementary examinations

Diagnostic

Their only formal indication is clinical doubt (notion of intermittent claudication of the lower limbs, presence of trophic disorders, etc.) as to the differential diagnosis between mediacalcosis and OSA. In this case, we will consider performing :

Measurement of perfusion pressures and arm-ankle index (ABI)

Doppler with perfusion measurements (ABI = Psystolic ankle / Psystolic arm, bilateral measurements for the arms, taking the highest value) is the first-line examination:

ABI > 1.3: mediacalcinosis

0.9 < ABI < 1.3: normal

ABI < 0.9: AOMI

However, it is not exceptional for mediacalcinosis to co-exist with an AOMI. In such cases, the ABI may be difficult to interpret (falsely "normal"). In the event of reasonable doubt, the following examinations should be performed.

Measurement of transcutaneous oxygen pressure

Perform at rest and during exercise. Normal values are between 40 and 80 mmHg. Lower pressures should raise suspicion of OSA.

Note that a hyperhaemia test with measurement of systolic tibial pressures is not reliable (as with ABI, values may be distorted if mediacalcinosis and ABI coexist).

Angiographic examinations

As these examinations are irradiating and/or require the injection of contrast products, they should be reserved for cases where the preceding examinations cannot rule out an AOMI, or in cases of very high clinical suspicion. In such cases, an angiography-CT-scanner, angiography-MRI or conventional angiography may be required to make the final decision.

"Aetiological" and miscellaneous

The existence of etiological factors other than senescence is not certain (see above). However, if a diagnosis of mediacalcinosis has been made, it seems reasonable to have a biology test (PTH, ionogram with calcium-phosphorus, renal function, glycated haemoglobin, pro-BNP) and a 24-hour ambulatory blood pressure holter (MAPA). Trans-thoracic echocardiography (TTE) may also be considered.

What are the medical implications?

The pathological implications of mediacalcosis are not certain. In any case, there is no specific treatment for this condition.

However, it seems reasonable to recommend screening and monitoring for cardiovascular risk factors and disorders of phospho-calcium metabolism.

Bibliography

Traité AKOS, Encyclopédie-médicochirurgicale, Elsevier, 2002

NB: this article, the first french version of which was written in 2014, has been, without being referenced, reproduced largely word for word without the use of quotation marks or any other marker by Dr. F.Z. Agharbi for the theoretical reminder section of an article published in french in PAMJ-Clinical Medicine in 2020. In 2023, Ms. V. Molinat, making at least an effort to rewrite, took over most of the information for an article published by the passeportsanté french website, also without any quotation or reference. In both cases, it's plagiarism and totally inappropriate.