Marfan Syndrome
What is Marfan Syndrome
Marfan syndrome is a genetic disorder that affects the normal development of connective tissue.
This has consequences at the level of different organs:
- Blood vessels
- Heart
- Lungs
- Eyes
- Skeleton
Estimated prevalence is 1 per 5,000-10,000 live births.
Why does Marfan Syndrome occur?
There is a mutation in the FBN1 gene that codes for fibrillin 1, a protein essential for the formation of elastic fibres.
It has an autosomal dominant inheritance pattern, if one parent has the disease, there is a 50% chance that the child will have the syndrome.
Up to 25% of people with Marfan syndrome have spontaneous de novo mutations (i.e. neither parent has passed on the abnormal gene).
What are the main manifestations?
- Aortic aneurysms (mainly in the root)
- Aortic dissection
- Mitral valve prolapse
- Pneumothorax (accumulation of air between the lung and chest cavity)
- Pectus carinatum/keeled pectus (protrusion of the sternum)
- Pectus excavatum / funnel-shaped (collapse of the sternum)
- Subluxation of the lens
- Myopia
- Dolichostenomelia (long, thin limbs)
- Arachnodactyly (very long fingers)
- Reduced elbow extension
- Acetabular protrusion (deformity of the hip joint)
- Flat feet
- Scoliosis (lateral deviation of the spine)
- Thoracolumbar kyphosis (excess curvature of the back)
- Dural ectasia
- Dolicocephaly (elongated head)
- Enophthalmos (sunken eyes)
- Malar hypoplasia (underdeveloped cheekbones)
- Retrognathia (retraction of the jaw)
What is the treatment?
Medical treatment: We recommend the use of beta-blockers (Atenolol, Bisoprolol), angiotensin receptor blockers ¨ARAII¨ (Losartan) or angiotensin converting enzyme inhibitors ¨IECA¨ (Enalapril).
Surgery: Preventive aortic root surgery is the mainstay of treatment in Marfan syndrome. In case of valve disease (mitral or aortic), valve repair should be considered in preference to prosthetic replacement.
When is surgery neccesary?
Type A aortic dissection: Emergent surgery with a high risk of complications and death.
Type B aortic dissection: Surgery if there is intractable pain, ischaemia of the kidneys, intestines or lower extremities, aortic diameter greater than 55 mm or rapid increase in the diameter of the artery.
Aneurysm or dilatation of the aortic root:
- In patients with no family history of aortic dissection/rupture: diameters equal to or greater than 50 mm or annual growth of 5 mm or greater.
- In patients with a family history of aortic dissection/rupture: diameters of 45 mm or more
Thoracoabdominal aneurysm: Surgery if aortic diameters are above 50 mm or when there is progressive growth greater than or equal to 5 mm/year.
Why is early surgery important?
Dilatation of the aorta causes a weakening of the vessel wall. The progressive growth of this wall, weakened by the disease, increases the risk of dissection and/or rupture of the aorta.
What is the technique?
Aortic valve reimplantation according to the David technique
This is the technique of choice when aortic root aneurysms are present and the aortic valve is structurally normal.
- A tubular Dacron® prosthesis is implanted from the origin of the aorta and the coronary arteries are reimplanted. The patient’s aortic valve is preserved and sutured inside the tubular prosthesis.
- It avoids the anticoagulation required with mechanical prostheses and is more durable than biological prostheses.
- It is the prosthesis of choice for young patients, athletes and women seeking pregnancy.
- Results: In-hospital mortality of patients undergoing planned surgery by our team is less than 1% and freedom from reoperation in the medium to long term is over 90%.
How affect pregnancy?
- Pregnancy is associated with an increased cardiovascular risk in Marfan syndrome, mainly in the third trimester of pregnancy and early postpartum.
- Aortic diameters above 4 cm in early pregnancy are closely related to aortic events.
- Consider prophylactic aortic root surgery with aortic diameters ≥ 4 cm in women desiring pregnancy.
- Genetic counselling is essential to know the risk of having offspring affected with the disease and to know the possible options for prenatal or pre-implantation diagnosis to select healthy embryos for Marfan syndrome.
Recomendations
Avoid contact sports, strenuous exercise to exhaustion and isometric activities. In the event of sudden onset, severe, stabbing pain in the back at the interscapular level, notify your doctor and go to the emergency department immediately.
