Mother: 49 years old, admitted in January 2014 with a preoperative diagnosis of Marfan’s syndrome aortic coarctation aneurysm type A3C and severe aortic valve closure insufficiency.On January 3, 2014, under general anesthesia, the aorta was cannulated via the right axillary artery. Aortic root replacement (Bentall) + full arch stent elephant trunk surgery (SUN’s) was performed with deep hypothermic stop circulation. He was discharged from the hospital after half a month of hospitalization and was followed for one year without recurrent entrapment at other sites and cerebrovascular events.
Son: 25 years old . admitted on January 14, 2015 with preoperative diagnosis of Marfan’s syndrome aortic coarctation aneurysm type A3S, severe aortic valve closure insufficiency, bilateral pulmonary alveoli and spontaneous pneumothorax. performed aortic root replacement (Bentall) + bilateral pulmonary alveolar resection with ligation under general anesthesia on January 23, 2015 with extracorporeal circulation. The day after surgery. He was awake and extubated from the trachea. Song Shiqiu, Cardiac Surgery Center, Beijing Anzhen Hospital
Marfan syndrome is a congenital mesodermal dysplasia, a genetic connective tissue disorder with autosomal dominant or autosomal recessive inheritance. The incidence of the syndrome varies, mainly involving the skeletal and cardiovascular systems, the eye and other organs and tissues. It was first reported by French pediatrician Antoine in 1896, and similar cases have been reported since then, and it was officially called Marfan syndrome in 1931.
The disease has a family tendency to develop and is autosomal dominant. The disease is intersexual, with no racial differences, and is seen in children as well as adults.
The disease is inherited in an autosomal dominant manner and is associated with the accumulation of mucopolysaccharides such as chondroitin sulfate A or C in many tissues such as endocardial valves, large blood vessels, and bones, which affects the structure and function of elastic and other connective tissue fibers, resulting in poor development and functional abnormalities in the corresponding organs. Abraham et al. (1982) suggested that abnormalities in aortic elastin, a decrease in bradykinin and isogranin, and a corresponding increase in lysyl residues are the main alterations in the disease, as is an increase in urinary hydroxyproline excretion and an increase in blood mucin and mucopolysaccharide.
The increased urinary hydroxyproline excretion in the patient is evidence of a deficiency in elastic fibers, or an abnormality in collagen metabolism, as evidenced by the family’s chain of gene location dominant inheritance. Connective tissue fibers are an important component of the body’s tissue structure, so when they become abnormal, they can affect organs (mesodermal tissues) throughout the body, especially in the skeletal and cardiovascular systems. In the spider finger as well as in the depressed or navicular thorax are indicated excessive growth of the tubular bones of the limbs, fingers and ribs longitudinally, probably as a result of defects in the fibrous component of the periosteum. There are acidic mucopolysaccharide deposits in the middle layers of the aorta and pulmonary arteries. The disease has a familial tendency and is inherited in an autosomal dominant fashion.
Most patients have symptoms from birth and have an older, sad appearance with a slender, underdeveloped trunk and thin subcutaneous fat.
Skeletal changes
Patients with this syndrome have long and thin extremities, especially the fingers (toes). The trunk may be shortened by lateral curvature and protrusion, making the limbs appear more elongated, like spider feet, hence the name spider fingers (Figure 1). Muscle tone is reduced, joint movement is increased, and there may be an abnormal range of motion, but dislocation is rare. The head is long, the forehead is rounded and convex, the sternal deformity is more common due to overgrown ribs funnel chest or chicken chest, and the scapula is elevated in a winged shape. Systemic connective tissue abnormalities can involve joint capsules, ligaments, tendons, and muscle membranes, which can lead to repeated joint dislocations, flat feet or high arched feet, high palatal arches, and uneven teeth. Common tests for Marfan syndrome include
(1) Metacarpal index: on the posterior anterior X-ray of both hands, the average length of the four metacarpals of the index finger, middle finger, ring finger and little finger is divided by the average width of the middle of the four metacarpals, the metacarpal index is less than 8 in normal people, and is greater than 8.4 in men and 9.2 in women in this syndrome.
(2) Thumb sign: The patient’s thumb was made to be inwardly extended across the palm and the fist was made. If the extended thumb is significantly beyond the ulnar border of the hand, it is positive.
(3) Wrist sign: The patient holds the contralateral wrist with one hand at the proximal end of the radial stem, and surrounds it with the thumb and little finger for 1 week. It is positive if the thumb and little finger can overlap each other without pressure.
Skin changes
The most common skin manifestations are widened skin lines or atrophic skin lines. These skin abnormalities can be seen in many parts of the body, especially in the chest, shoulder deltoid area and thighs.
Cardiovascular abnormalities
The most common cardiovascular abnormalities are idiopathic dilatation of the aorta, aortic coarctation aneurysm and mitral valve abnormalities. Sometimes both aortic and mitral valve lesions can occur. In addition, trauma, hypertension, and pregnancy can induce acute aortic dissection and coarctation aneurysm formation. In addition to aortic and mitral valve lesions, tricuspid valve lesions can sometimes occur. Although aortic dilatation always occurs in the ascending aorta, aneurysmal dilatation, entrapment aneurysm formation or rupture can also occur in the thoracic and abdominal aorta. Other rare cardiovascular complications include dilatation of the Faure’s sinus and pulmonary artery, dilatation of major branches of the aorta such as the common carotid artery and splenic artery, endocardial fibrous aortic aneurysm rupture and heart failure are the main causes of death in this syndrome.
Ocular changes
The most characteristic manifestation is crystal dislocation or hemianopsia, which is bilateral in about 3/4 of patients. The dislocation of the lens can be caused by a variety of factors. Large eyes and small crystals can result in an enlarged periocular space, extension of the suspensory ligament, ciliary dysplasia, and abnormalities of the suspensory ligament and its attachment to the lens. In addition, this syndrome may present with ocular abnormalities such as high myopia, glaucoma, retinal detachment, and iritis. These ocular pathologies have a more serious impact on the eye than crystal dislocation. Sclera Abnormalities manifest as a blue sclera. Sometimes corneal overgrowth, retinitis pigmentosa, choroidal sclerosis, strabismus, nystagmus, blepharospasm, and anterior chamber shallowing may also occur
Neurological lesions
The neurological symptoms of this syndrome, like other congenital rheumatic diseases, are caused by cerebrovascular malformations and manifest as subarachnoid hemorrhage and grand mal seizures due to compression symptoms aneurysms caused by internal carotid artery aneurysms. In addition, patients with Marfan syndrome can also develop spina bifida spinalis spinalis spinalis bulge, spinal cord cavernosa. Hypotonia with myasthenia gravis is the most common neuromuscular symptom of this syndrome. A small number of patients may have mental retardation or dementia.
Complications
Cardiovascular complications include idiopathic dilatation of the aorta, aortic stenosis, aortic coarctation aneurysm, and mitral valve anomalies.
2. Ocular lesions can be complicated by crystal dislocation or subluxation, high myopia, glaucoma, retinal detachment, iritis, etc.
Neurological lesions can be complicated by subarachnoid hemorrhage and internal carotid aneurysm, and grand mal seizures. In addition, patients with Marfan syndrome can also occur spina bifida spinal cord bulge, spinal cavernous disease.
7 Laboratory tests
1. slit lamp examination to determine the presence or absence of lens ectasia.
2. X-ray examination: finger bones slender, metacarpal index ≥ 8.4, (i.e., the ratio of the length and width of the right 2nd-5th metacarpal), the normal 5.5-8.0.
3. echocardiography: aortic root dilatation, aortic valve insufficiency and other complicating cardiac malformations are seen.
4. CT, MRI. More accurate than echocardiography.
8 Diagnosis
1. The diagnosis of this syndrome is based on
(1) Special skeletal changes, i.e., elongated tubular bones, especially in the fingers and metacarpals. The bone cortex is thin and slender, showing spider finger-like changes.
(2) Congenital cardiovascular abnormalities
(3) Ocular symptoms.
(4) Family history.
The diagnosis can be confirmed by three of the above four clinical criteria, and incomplete Marfan syndrome can be diagnosed with only two of the first three changes
2. Mckusick (1995) classified the cardiovascular abnormalities of Marfan syndrome as
(1) Aortic dilatation (ascending and descending aorta), aortic coarctation aneurysm, aortic stenosis, and patent ductus arteriosus.
(2) Pulmonary artery anomalies (pulmonary artery dilatation, pulmonary aneurysm).
(3) Septal defects (atrial septal defect, ventricular septal defect).
(4) Valvular anomalies and concomitant subacute bacterial endocarditis.
Differential diagnosis.
This disease needs to be differentiated from the following diseases.
1. Ai-dang syndrome Although symptoms of overgrown extremities and joint hyperactivity may be present, symptoms of skin and vascular fragility and skin hyperextension are not present in Marfan syndrome.
2. Elastic pseudoxanthomatosis Aortic aneurysms and flaccid lesions may occur The lesions are papules or macules with clear borders in a punctate, round or oval shape or fused into patches with localized elevation In addition, the disease has characteristic retinal vascular-like pigmented texture. There is no joint hyperactivity nor limb bone elongation or spider fingers.
Homocystinuria is a congenital abnormality of methionine metabolism with crystal dislocation, abnormal limb thorax and spinal abnormalities. However, abnormalities of urine systemic osteoporosis, vascular embolism and unresponsiveness are not present in Marfan syndrome.
9 Treatment
There is no specific treatment, and ocular anomalies can be treated with appropriate surgery or medication. Aortic lesions can be treated with propranolol (Takayasu) to reduce ventricular blood displacement and pressure and reduce the impact on the aortic wall, thus delaying the development of aortic root dilatation and preventing aortic coarctation aneurysms For female patients before puberty, estrogen and progesterone can be taken to advance puberty and prevent scoliosis deformity due to excessive growth In patients with severe thoracic and spinal deformities, the Patients with moderate aortic valve atresia insufficiency or marked dilatation of the aortic root can be treated surgically.
10 Prognosis Prevention
Prognosis
The prognosis is good, with most patients surviving to middle age, often dying from aortic aneurysm rupture and heart failure.
Once a patient with Marfan syndrome is diagnosed, he should be reviewed regularly. Once ruptured aortic coarctation, massive aortic regurgitation, enlarged left ventricle, or ascending aortic diameter greater than 5 CM. or ascending aortic diameter increasing by 5 mm within six months, surgery should be performed. At present, open surgery and stent endoluminal treatment of aortic coarctation aneurysm in the author’s surgical group is a routine procedure, and the success rate of the surgery is more than 95%.