Aortic Stenosis is a condition where the aortic valve of the heart becomes narrowed. This leads to obstructed blood flow to the aorta from the left ventricle. Aortic Stenosis is more common among men. Elderly persons are likely to face this heart valve disease. When the narrowing of the aortic valve is to a small extent, the patient does not feel any discomfort or other symptoms. But when there is significant reduction in the valve area, it leads to decrease in cardiac output and may result in heart failure. Aortic valve stenosis must not be ignored as it systematically weakens the heart. It forces the left ventricle to work harder.
Aortic Stenosis is often caused by rheumatic fever, calcification of the valve, coronary artery disease or heart murmur. Symptoms of aortic stenosis include chest pain (angina), shortness of breath and fainting spells. They occur due to the heart muscle's inability to cope up with the extreme pressure load laid by Aortic stenosis. Patients suffering from aortic stenosis are likely to feel palpitations, dizziness and chest pain on exertion.
Enlargement of the left ventricle or Aortic stenosis can be diagnosed with the aid of Doppler ultrasound, echocardiogram, chest x-ray and trans esophageal echocardiogram. The physician will be able to notice arrhythmia and enlargement of left ventricle. Diuretics are prescribed to reduce high lung pressure. Blood thinners are used to prevent blood clots from being formed on the surface of the heart valves. Replacement of aortic valves is done in severe cases of valvular failure. Balloon valvuloplasty is a surgical procedure similar to balloon Angiography where a balloon is placed in an artery and later inflated to relieve obstruction.
Fetal surgery refers to the surgical treatment of the developing baby in the womb to rectify congenital defects. Surgery of the fetus is performed to fix the prenatally diagnosed anomalies. However fetal surgery is a complicated procedure and comes with lot of risks to both mother and the baby. Yet, doctors recommend fetal surgery, if the risks associated with continuing the pregnancy, without surgical intervention, outweighs the risks that come with fetal surgery. Certain abnormalities, if left to progress in the womb, may turn fatal and infant may die soon after the birth. However fetal intervention is initiated only after taking the safety of the mother into consideration. The common risks that are associated with fetal surgery are premature delivery, infection of the uterus, leaking of amniotic fluid through the membrane, potential infertility and the risk of anesthesia.
There are various techniques followed to diagnose fetal anomalies. The diagnostic method can be non invasive such as ultrasound, fetal echocardiography, MRI, Radiography, Measuring MSAFP (maternal serum alpha-fetoprotein) and Measuring maternal serum beta-human chorionic gonadotropin (HCG) or invasive procedure such as amniocentesis, Chorionic villus sampling and Percutaneous umbilical blood sampling (PUBS) are used to detect the birth defects.
Types of Fetal Surgery
Depending on the incision level, fetal surgery is classified into three types.
Open Fetal Surgery
Open fetal surgery is almost similar to cesarean section and involves a total opening of the uterus. In this type of surgery, a long incision is made in the mother's abdomen and then on the uterus to reach the fetes. Once the surgical correction is performed on the fetus to treat the birth defect, the uterus and abdominal is closed back leaving the fetus intact. Open fetal surgery is performed under general anesthesia. Surgery is performed using special instruments containing staples to prevent bleeding from uterus. During the operation, warm saline water is infused to maintain the position of placenta and umbilical cord and surgeon will keep a vigil on the pulse and heart rate of the baby with the help of the oximeter. After the surgery, the mother is hospitalized for close to a week to facilitate close monitoring. One should remember that, with open fetal surgery, mother will forgo the option of vaginal delivery for the present and future deliveries. She can deliver the baby only through C-section. She may be given some medication to avoid pre term labor. Open fetal surgery is followed for the conditions like chest mass, neck mass, spinbifida, myelomeningocele and Sacrococcygeal teratoma (SCT) (a tumor at the base of the child's tail bone).
There is one more variation to the open fetal surgery called the EXIT (Ex Utero Intrapartum Treatment) Procedure. EXIT surgery is performed at the end of the full term and just before the delivery. In this method the baby is partially delivered by bringing out only a part of the fetes from uterus and keeping rest of the fetes attached to placenta and umbilical cord to allow blood circulation. Once the defect is rectified, the baby is delivered fully. Exit procedure is essentially followed to correct the airway blockage in the baby.
Fetoscopic surgery is minimally invasive and unlike open fetal surgery, fetes remains inside the uterus while operating. Surgeon uses special instruments such as laser and makes a small incision with the help of the fetoscope to correct the birth defects. Fetoscopic surgery has shown high success rate in conditions such as Twin-Twin Transfusion Syndrome (TTTS), Twin Reversed Arterial Perfusion (TRAP), Amniotic band syndrome, and Tracheal occlusion for CDH. Fetoscopic surgery does not pose a risk of pre term labor and also eliminates most of the risks associated with open fetal surgery. This is essentially why fetoscopic surgery is the preferred choice, yet one should note that few complicated birth defects can be corrected only through open fetal surgery.
Fetal image guided surgery
Fetal image guided surgery is the least invasive of all wherein surgery is performed with the guidance of images of fetus produced on the external screen by ultrasound. Very thin instruments are inserted through a small opening in the abdomen and the correction is made without any endoscopic view and the whole procedure is guided by the sonogram images.
Various congenital conditions treated through fetal intervention
Congenital diaphragmatic hernia (CDH): Congenital diaphragmatic hernia (CDH) refers to the opening in the diaphragm through which the contents of the abdomen enter the chest cavity leaving no space for the lungs to develop properly. This is a serious condition and may lead to respiratory failure after birth. This condition, depending upon its severity, is treated through fetal intervention.
Spina bifida: Spina bifida refers to a condition wherein spinal column of the baby does not close properly around the spinal cord and the nerves start to protrude through the opening. Spina bifida can range from mild to severe form, and the severe cases lead to serious neurological problems after the birth. Only the severe form of spina bifida like Meningocele and Myelomeningocele call for fetal intervention through open fetal surgery.
Neck masses: Neck masses are the tumors of the neck that may obstruct the airway and esophagus of the child and also increase the level of amniotic fluid surrounding the baby. Typically, tumors of any kind are treated after birth. In rare cases they grow very large and may even cause heart failure. In such cases fetal intervention becomes necessary to remove the tumors.
Lung lesions: Lung lesions refer to the abnormal growth of lung tissue and these lesions can be cystic (fluid filled) or solid. There are various types of lung lesions and treatment depends upon their size and location. During pregnancy, continuous monitoring is necessary to keep vigil on the size of the lesion. Most often lung lesions shrink and make way for normal development. Lesions of smaller and moderate size are best treated after delivery. But if the size of the lung tumor is abnormally huge and poses a risk of hydrops (excess accumulation of fluid in the fetus) fetal intervention is initiated. Cystic lesions are normally removed through needle aspiration under the constant guidance of ultrasound images, but solid lesions require more elaborate procedure such as EXIT.
Congenital heart diseases: Not all congenital heart defects call for fetal intervention. Sometimes the septum (wall separating the right and left side of the heart) of the heart develops a hole while in the womb. However septum defects are typically treated after the birth of the child and rarely require fetal surgery. But if the heart develops severe obstructive cardiac disorders such as aortic stenosis, pulmonary stenosis and coarctation of the aorta,a fetal image-guided procedure may be necessary to open or enlarge the narrowed valve. This procedure involves placing a balloon catheter by inserting it through the uterus and into the fetal’s heart.
Amniotic Band Syndrome: This is a condition where fetus is entrapped in fibrous amniotic bands in the womb, restricting blood flow to the affected portion of the fetes. It normally affects legs, arms, toes and fingers. In utero surgery may be performed to rectify the condition if there is risk of amputation of the limb after the birth.
Twin-to-twin transfusion syndrome (TTTS): TTTS is a condition that occurs in identical twins wherein unbalanced exchange of blood takes place between the twins. One receives higher amount of blood whereas the other receives less amount. The fetus with less blood supply may become anemic and the one with excess blood supply may suffer heart failure due to excess fluid. Fetal surgery through laser fetal intervention is the preferred option to correct the condition. This procedure involves inserting a laser along with small telescope into the uterus and separating the blood vessels on the placenta that are connected to both twins.
Congenital high airway obstruction syndrome (CHAOS): Congenital high airway obstruction syndrome (CHAOS) refers to the blocking of fetal airway resulting in enlarged lungs, windpipe and bronchial tube. A complete or near to complete blockage may lead to a heart failure. Though congenital high airway obstruction syndrome (CHAOS) is treated after birth, in severe cases where fetes is at high risk such as hydrops, fetal surgery is performed.
An unusually cheerful demeanor and ease with strangers and charming facial appearance along with a low nasal bridge are characteristics of Williams Syndrome or Williams-Beuren syndrome. On the other hand, developmental delay, language deficiency, visual and spatial impairments, cardiovascular problems and high blood calcium are also features of Williams Syndrome in the very same person.
To put it in other words, this is a developmental disorder that affects many parts of the body, characterized by mild to moderate intellectual disability, some exceptional personality features such as distinctive facial features, heart and blood vessel problems. Identified by JCP Williams, a New Zealander in 1961, this syndrome is named after him. Williams Syndrome has many names such as Beuren syndrome, Elfin Facies Syndrome with Hypercalcemia, Supravalvar Aortic Stenosis Syndrome and Williams Beuren syndrome. It is usually diagnosed before age 4.
Williams Syndrome is caused when about 26 genes from the chromosome 7 are spontaneously micro-deleted. Occurrence of this disease is 1: 7500 to 1: 20000 births. As several genes are lost in this deletion, researchers opine that the loss can contribute to the characteristic features of this disorder. Some of the genes typically deleted in this syndrome are CLIP2, ELN, GTF2I, GTF2IRD1, and LIMK1.
Most do not inherit this syndrome. The deletions of chromosomes are only due to random events that occur in eggs or sperm from their parents. Loss of ELN gene which codes for protein elastin can cause full cheeks, coarse voice, hernias and bladder diverticulitis. Deletion of other genes causes characteristics such as visual-spatial deficiency. Deficiency of other genes such as CLIP2, can contribute to learning disabilities and other cognitive difficulties associated with this syndrome.
Perhaps the most common symptom of this syndrome is heart defects followed by unusual facial features. These include Elfin-like facial features, including upturned nose and prominent lips, an abnormally small head, vertical skin folds that cover the inner corners of the eyes and sunken chest.
Trouble to gain weight as a baby, low muscle tone and a height lower than expected, are other signs. Those with this syndrome tend to have gaps in teeth, a flattened nasal bridge and an unusually longer philtrum (the vertical groove between the base of the nose and the border of the upper lip). Those affected have teeth that are small, crooked or missing.
These are 'cocktail party' type personalities, highly talkative and overly sociable. They develop hyper focus that is deep and intense concentration of the eyes while socially engaged, which could be very embarrassing.
Attention deficit disorder, developmental delays and far sightedness are characteristic of these syndrome personalities. While those with Williams syndrome tend to be more sociable than autistic persons, they have impairment in cognitive function with visuo-spatial impairments.
Recognition of physical symptoms by a pediatrician followed by confirmatory genetic test is the basis of diagnosis for this syndrome. A pediatrician looks at some significant external physical signs characteristic of this syndrome including puffiness around the eyes, long philtrum and stellate pattern (arranged in a radiating pattern like that of a star) in the iris. Some less reliable symptoms of this disorder are anteverted nostrils, a wide mouth and elongated neck.
Physiological symptoms include cardiovascular problems, feeding disturbance in infants. Developmental delay is also an initial sign of this disorder. Pediatrician may also look at ultrasound to check the child's heart for irregularities. Two possible genetic tests to diagnose this order are micro-assay analysis and fluorescent in situ hybridization (FISH) test. These two genetic tests are more or less confirmatory in identifying Williams Syndrome than previous methods which simply relied on cardiovascular problems and facial features.
As such, this syndrome has no cure. Recommendations include avoidance of extra calcium and vitamin D and treating high levels of blood calcium. While narrowing of blood vessels can be a significant health problem, this can be treated on an individual basis. Those with joint stiffness and low muscle tone can be given physical therapy. Developmental and speech therapies are normally given to children to increase their social interactions.
Annual cardiological evaluation is recommended for those with Williams Syndrome. Ophthalmic evaluations and examination for hernia, hearing assessments, blood pressure measurement, developmental and growth evaluation, ortho assessment of joints, muscle tone and assessments of diet and feeding to manage constipation and urinary problems are suggested.
Management of Williams Syndrome
This is a syndrome that cannot be cured but can be managed. Early medical evaluation and treatment can go a long way in managing certain developmental delays and heart problems. It is important for family members to remember that this is a rare condition and that the affected individual cannot be expected to live a normal life due to complications arising out of the disease.
Music is viewed by some as one of the most effective treatment for this syndrome. Music helps in healing the internal and external anxiety of those afflicted.
Bibliography / Reference
Collection of Pages - Last revised Date: February 21, 2019