Cyanosis medical therapy
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief:
Overview
There is no treatment for [disease name]; the mainstay of therapy is supportive care.
OR
Supportive therapy for [disease name] includes [therapy 1], [therapy 2], and [therapy 3].
OR
The majority of cases of [disease name] are self-limited and require only supportive care.
OR
[Disease name] is a medical emergency and requires prompt treatment.
OR
The mainstay of treatment for [disease name] is [therapy].
OR The optimal therapy for [malignancy name] depends on the stage at diagnosis.
OR
[Therapy] is recommended among all patients who develop [disease name].
OR
Pharmacologic medical therapy is recommended among patients with [disease subclass 1], [disease subclass 2], and [disease subclass 3].
OR
Pharmacologic medical therapies for [disease name] include (either) [therapy 1], [therapy 2], and/or [therapy 3].
OR
Empiric therapy for [disease name] depends on [disease factor 1] and [disease factor 2].
OR
Patients with [disease subclass 1] are treated with [therapy 1], whereas patients with [disease subclass 2] are treated with [therapy 2].
Medical Therapy
- Conditions associated with decreased concentration of inspired oxygen:
- Smoke inhalation most commonly from house fires
- Carbon monoxide poisoning
- cyanide poisoning
- Pneumothorax
- Foreign body aspiration
Surgical closure is the most common method of treatment method for atrial septal defect and has been the gold standard for many years. Many surgeons prefer more minimally invasive techniques over the conventional sternotomy to avoid potentials for additional complications. Special consideration must be taken into account for the age of the patient and the size of the defect involved. Surgical closure is indicated for patients with primum, sinus venosus and coronary sinus type of atrial septal defects. However, ostium secundum atrial septal defects are commonly treated by percutaneous closure. With uncomplicated atrial septal defect, (without pulmonary hypertension and other comorbidities) the post-surgical mortality is as low as 1%.
Minimally invasive repair of atrial septal defect has been shown to be as successful as the conventional sternotomy. Although they have not been associated with reduced morbidity and mortality rates, they have been proven to have the advantage of being less invasive, less post-surgical complications, decreased hospital stay, and more cosmetic benefits.
The choice of treatment for pulmonary hypertension (PH) requires the assessment of the clinical severity of the disease and the identification of any underlying cause. Patients who have PH secondary to a medical condition such as left heart failure, lung diseases, or thromboembolic disease (PH group 2, 3, and 4 respectively) should receive treatment for the underlying cause. Patients who have pulmonary arterial hypertension (PAH) must undergo vasoreactivity testing in order to assist in the selection of the optimal therapy which includes calcium channel blockers, endothelin receptor antagonist, phosphodiesterase inhibitors, or prostanoids.
Surgical intervention such as atrial septostomy or lung transplantation should be considered among patients with pulmonary arterial hypertension (PAH) who fail to improve on optimal therapy or when medical therapy is unavailable.
Failure of clinical improvement among PAH patients with WHO functional class II or III is defined as either:
- A stable and unsatisfactory clinical status, or
- An unstable and deteriorating
Failure of clinical improvement among PAH patients with WHO functional class IV is defined as either:
- Absence of quick improvement to a WHO functional class III or less, or
- A stable and unsatisfactory clinical status
Atrial Septostomy
- Atrial septostomy is a surgical procedure that creates a shunt between the right and left atria.
- It relieves pressure on the right side of the heart, but at the cost of lower oxygen levels in blood (hypoxia). It is best performed in experienced centers.
- Graded balloon dilatation of atrial septostomy is the recommended type of atrial septostomy.
- Atrial septostomy might be considered among PH patients with WHO functional class IV and right heart failure refractory to therapy.
- Atrial septostomy should also be considered among PH patients who have Eisenmenger's syndrome, idiopathic PAH, and those awaiting lung transplantation.
Lung Transplantation
- Lung transplantation is considered in the treatment of patients with idiopathic PH, PH associated with congenital heart disease, or pulmonary veno-occlusive disease (PVOD) who fail to improve on optimal medical therapy.
- Combined lung and heart transplantation might be considered in selected patients.
- According to the Registry of the International Society for Heart and Lung Transplantation, the survival rates following lung transplantation are 61%, 49%, and 25 % at 3, 5, and 10 years respectively.
Pulmonary Thromboendarterectomy
- Pulmonary thromboendarterectomy (PTE) is a surgical procedure that is used for the treatment of chronic thromboembolic pulmonary hypertension.
- It is the surgical removal of an organized thrombus along with the lining of the pulmonary artery.
- PTE is a large and very difficult procedure that is currently performed in a few select centers. Case series show remarkable success in most patients.
- Treatment for hypoxic and miscellaneous varieties of PH have not been established. However, studies of several agents are currently enrolling patients. Many physicians will treat these diseases with the same medications as for PAH, until better options become available.
- Methemoglobinemia is treated with supplemental oxygen and methylene blue 1% solution (10mg/ml) 1-2mg/kg administered intravenously slowly over five minutes followed by IV flush with normal saline. Methylene blue restores the iron in hemoglobin to its normal (reduced) oxygen-carrying state. This is achieved through the enzyme inducing effect of methylene blue on levels of diaphorase II (NADPH methemoglobin reductase). Diaphorase II normally contributes only a small percentage of the red blood cells reducing capacity but is pharmacologically activated by exogenous cofactors, such as methylene blue, to 5 times its normal level of activity. Genetically induced chronic low-level methemoglobinemia may be treated with oral methylene blue daily.
Raynaud's phenomenon
- Drug treatment is normally with a calcium channel blocker, frequently nifedipine to prevent arterioconstriction. It has the usual side effects of headache, flushing, and ankle edema, and patients often stop treatment, preferring the symptoms of Raynaud's to the symptoms of the drug.
- The extract of the Ginkgo biloba leaves (Egb 761, 80mg) reduces symptoms in two weeks.
- There is some evidence that Angiotensin II receptor antagonists (often Losartan) reduce frequency and severity of attacks.
- In intractable cases, sympathectomy and infusions of prostaglandins, e.g. prostacyclin, may be tried, with amputation in exceptionally severe cases.
- Alpha-1 adrenergic blockers such as prazosin can be used to control Raynaud's vasospasms under supervision of a health care provider.
- In a study published in the November 8, 2005 issue of Circulation, sildenafil (Viagra) improved both microcirculation and symptoms in patients with secondary Raynaud's phenomenon resistant to vasodilatory therapy. The authors, led by Dr Roland Fries (Gotthard-Schettler-Klinik, Bad Schönborn, Germany), report: "In the present study, capillary blood flow was severely impaired and sometimes hardly detectable in patients with Raynaud's phenomenon. Sildenafil led to a more than 400% increase of flow velocity."
- Two separate gels combined on the fingertip (somewhat like two-part epoxy, they cannot be combined before use because they will react) increased blood flow in the fingertips by about three times. One gel contained 5% sodium nitrite and the other contained 5% ascorbic acid. The milliliter of combined gel covered an area of ~3 cm². The gel was wiped off after a few seconds. Tucker, A.T. et al., The Lancet, Vol. 354, November 13, 1999, pp..
Peripheral vascular disease
Medical Therapy for Acute Occlusion
- Urgent measures should be taken to ensure blood flow and protect the limb:
- ICU admission
- Administration of heparin for anticoagulation
- Electrolytes, acid- base and renal status monitoring
- Limb status monitoring and frequent assessment of the need for fasciotomy.
- If the limb is not immediately threatened:
- Continue treatment with thrombolytic therapy for 14 days.
- If the limb ischemia is critical:
- Consider percutaneous transluminal angioplasty
- Consider surgery: thromboembolectomy, bypass grafting
- Send sample for pathologic examination (myxoma may be present)
Reduction in Modifiable Cardiovascular Risk Factors[edit | edit source]
- Diabetes control
- Hypertension treatment
- Dyslipidemia treatment
- Smoking cessation
Improvement of the Walking Ability[edit | edit source]
Exercise Rehabilitation[edit | edit source]
- A regular walking program four times a week for six month results in an average of 6.5 minutes improvement in the walking time.
- It opens up collateral circulation.
- It reduces cardiovascular mortality.
- It improves quality of life.
Cilostazol[edit | edit source]
- Cilostazol is a phosphodiesterase III inhibitor.
- It is FDA approved.
- Cilostazol is not administered to all PAD cases but rather to selected cases where regular walking program has failed to improve the walking time and capacity.
- It is contraindicated in congestive heart failure.
- Side effects:
- Headache
- Diarrhea
- Gastric upset
- Palpitations
- Dizziness
The Choice of the Revascularization Intervention Based on TASC Classification[edit | edit source]
For detailed information regarding the TASC classification, click here.
Iliac Lesions[edit | edit source]
- Endovascular revascularization is the intervention of choice in patients with TASC type A iliac lesions.
- TASC type A iliac lesions is defined as a single stenosis less than 3 cm of the common iliac artery or external iliac artery (unilateral/bilateral).
- Surgical revascularization is the intervention of choice in patients with TASC type D iliac lesions.
- TASC type D iliac lesions is defined as either one of the following:
- Diffuse, multiple unilateral stenoses involving the common iliac artery, external iliac artery, and common femoral artery (usually more than 10 cm long)
- Unilateral occlusion involving both the common iliac artery and external iliac artery
- Bilateral external iliac artery occlusions
- Diffuse disease involving the aorta and both iliac arteries
- Iliac stenoses in a patient with an abdominal aortic aneurysm or other lesion requiring aortic or iliac surgery.
- TASC type D iliac lesions is defined as either one of the following:
- As for TASC type B iliac lesions and TASC type C iliac lesions, the choice between endovascular and surgical revascularization requires the evaluation of the percentage of artery stenosis.
Femoral Lesions[edit | edit source]
- Endovascular revascularization is the intervention of choice in patients with TASC type A femoropopliteal lesions.
- TASC type A femoropopliteal lesions is defined as a single stenosis less than 3 cm of the superficial femoral artery or popliteal artery.
- Surgical revascularization is the intervention of choice in patients with TASC type D femoropopliteal lesions.
- TASC type D femoropopliteal lesions is defined as complete common femoral artery or superficial femoral artery occlusions or complete popliteal and proximal trifurcation occlusions.
- As for TASC type B femoropopliteal lesions and TASC type C femoropopliteal lesions, the choice between endovascular and surgical revascularization is not definite.
Endovascular Revascularization Modalities[edit | edit source]
- PTAC ( Percutaneous transluminal angioplasty)
- Stents
- Atherectomy
- Laser
- Cutting balloons
- Thermal angioplasty
- Fibrinolysis/Fibrinectomy
Initial management of neonantal cyanosis
Newborns with cyanosis require maintains adequate tissue perfusion and oxygenation.
Specific interventions for neonatal cyanotic congenital heart disease (CHD) include administration of prostaglandin E1 and cardiac catheter palliative or corrective procedures.
Initial management begins with general care that includes
cardiorespiratory support
monitoring to ensure sufficient organ/tissue perfusion and oxygenation
an adequate airway should be established immediately and supportive therapy (eg, supplemental oxygen and/or mechanical ventilation) instituted as needed.
Placement of secure intravenous and intraarterial catheters is most easily accomplished via the umbilical vessels.
This will enable efficient correction and monitoring of acid-base balance
metabolic derangements (eg, hypoglycemia, hypocalcemia), and blood pressure.
Inotropic agents such as dopamine or dobutamine may be necessary to correct hypotension.
In infants with severe polycythemia (>70 percent), an isovolumetric partial exchange transfusion should be performed with saline to reduce the hematocrit.
Hypoglycemia is common in critically
ill infants, therefore glucose levels should be monitored and glucose infusions provided to
maintain a blood glucose > 55 mg/dL. An airway and assisted ventilation should be considered
for infants with respiratory distress, but may be deferred for the comfortable infant.
Severe
acidosis should be corrected with infusions of sodium bicarbonate, but only after adequate gas
exchange has been established. If the infant is <10 days old and the umbilical stump is still
attached, umbilical venous and arterial lines can frequently be placed by experienced
Steinhorn
Hypocalcemia is often associated with cardiac disease
and critical illness, and should be corrected based on the ionized calcium.
Oxygen should be provided, although there are increasing concerns about the potential risks
associated with this therapy (6). Even brief (30 minute) exposures to extreme hyperoxia are
increasingly recognized to increase oxidative stress and potentially damage lung parenchymal
and vascular function, even in term infants (7. 8).
the use of 100% O2 should
generally be avoided at the outset. Initiating oxygen therapy with 40–60% O2 will allow the
caregiver to provide support, assess for improvement, and seek advice from a cardiologist.
This
point is particularly important if an infant has only a minimal response to oxygen, as this may
indicate potential cardiac disease and need for PGE1. In addition, it is important to remember
that oxygen may promote ductal closure. This may not be a major concern for lesions that limit
pulmonary blood flow, as the pulmonary venous PO2 would not be expected to rise.
However,
admixture lesions such as hypoplastic left heart syndrome may present with moderate cyanosis.
These conditions are dependent on a patent ductus to maintain systemic blood flow. Oxygen
may not only promote ductal closure, but may increase pulmonary and decrease systemic blood
flow.
In the infant who does not require assisted ventilation, oxygen may be delivered via a head
hood or nasal cannula (9). A head hood is the only method that allows the FiO2 to be determined
precisely.
The oxygen concentration should be measured by an oxygen analyser placed near
the baby’s mouth. Relatively high flows are needed achieve adequate concentrations of oxygen
and avoid carbon dioxide accumulation, although humidification is generally not necessary.
While head box oxygen is generally well tolerated, this method limits the infant’s mobility,
and oxygen concentrations fall quickly when the hood is lifted to provide care to the infant.
Oxygen is frequently delivered by a nasal cannula. The disadvantage of this method is that the
infant entrains variable amounts of room air around the nasal cannula. Therefore, it cannot
provide 100% oxygen, and the oxygen concentration in the hypopharynx (a good proxy for the
tracheal concentration) will be much lower than the concentration of oxygen at the cannula
inlet. Both the oxygen concentration and the cannula flow rate will be the major factors that
will determine the fraction of oxygen actually delivered. Therefore, it is generally better to
titrate delivery to achieve the desired oxygen saturation levels, generally 90% to 95% by pulse
oximetry.
Antibiotics
broad spectrum antibiotics should be initiated (ampicillin and gentamicin) after obtaining blood and urine cultures.
Specific CHD measures
An infant who fails the hyperoxia test and does not have persistent pulmonary hypertension of the newborn or a chest radiograph consistent with lung disease is likely to have a cyanotic CHD. In most cases, cyanotic CHD is dependent upon a patent ductus arteriosus (PDA) for pulmonary or systemic blood flow. Closure of the ductus arteriosus can precipitate rapid clinical deterioration with significant life-threatening changes (ie, severe metabolic acidosis, seizures, cardiogenic shock, cardiac arrest, or end-organ injury).
As a result, infants with ductal-dependent lesions are at increased risk for death and significant morbidity unless interventions are initiated to maintain patency of the ductus arteriosus for ductal-dependent lesions, ensure adequate mixing of deoxygenated and oxygenated blood, or relieve obstructed blood flow.
In infants with or who have a clinical suspicion for a ductal-dependent congenital heart defect, prostaglandin E1 (alprostadil) should be administered until a definitive diagnosis or treatment is established [7].
The initial dose is dependent on the clinical setting, as the risk of apnea, one of the major complications of prostaglandin E1 infusion, is dose dependent.
●If the ductus is known to be large in a patient with duct-dependent physiology, the initial dose is 0.01 mcg/kg per minute. This scenario typically is seen in patients with echocardiographic confirmation of a large PDA who are cared for in a tertiary center that provides treatment for neonates with cyanotic heart disease.
●If the ductus is restrictive or the status of the ductus is unknown, the initial dose is 0.05 mcg/kgper minute. This is the standard dose used in patients who require transport to a center with expertise in the care of neonates with cyanotic heart disease.
The dose of prostaglandin can be increased as needed to a maximum dose of 0.1 mcg/kg per minute.
Complications of prostaglandin E1 infusion include hypotension, tachycardia, and apnea [8]. As a result, a separate reliable intravenous catheter must be in place to provide fluids for resuscitation. Intubation equipment should be immediately available because apnea can occur at any time during infusion.
Deterioration of the clinical status after starting prostaglandin E1 usually indicates the presence of rare congenital cardiac defects associated with pulmonary venous or left atrial obstruction. These include obstructive (usually infradiaphragmatic) total anomalous pulmonary venous connection or various conditions associated with a restrictive atrial septum (eg, hypoplastic left heart syndrome, cor triatriatum, severe mitral stenosis or atresia, or D-transposition of the great arteries associated with restrictive atrial shunting). These patients require urgent echocardiography followed by interventional cardiac catheterization or surgery [9].
Cardiac catheterization
Cardiac catheter interventions can either be palliative by improving cyanosis or be corrective by relieving obstruction to flow.
●Balloon atrial septostomy can relieve marked cyanosis in patients with D-transposition of the great arteries associated with restrictive atrial shunting, and in patients with a restrictive atrial septum associated with left-sided obstructive disease. In patients with D-transposition of the great arteries, this procedure can be performed at the bedside under echocardiographic guidance. (See "Management and outcome of D-transposition of the great arteries", section on 'Balloon atrial septostomy' and "Hypoplastic left heart syndrome: Management and outcome", section on 'Initial medical management'.)
●Balloon valvuloplasty can be effective in patients with critical pulmonary stenosis or aortic stenosis. Selected patients with pulmonary atresia are also candidates for balloon valvuloplasty if the obstruction is membranous, the tricuspid annulus and right ventricular size are adequate to support a two ventricle repair, and the coronary circulation does not depend upon the right ventricle [10]. (See "Valvar aortic stenosis in children", section on 'First-line treatment'.)
●Transcatheter occlusion of pulmonary arteriovenous malformations can also be performed [11].
Palliative Surgery
- The condition was initially thought untreatable until surgeon Alfred Blalock, cardiologist Helen B. Taussig, and lab assistant Vivien Thomas at Johns Hopkins University developed a surgical procedure. It was actually Helen Taussig who convinced Alfred Blalock that the shunt was going to work.
- The surgery involved forming an anastomosis between the subclavian artery and the pulmonary artery. This redirected a large portion of the partially oxygenated blood leaving the heart for the body into the lungs, increasing flow through the pulmonary circuit, and greatly relieving symptoms in patients.
- The first Blalock-Thomas-Taussig shunt surgery was performed on 15-month old Eileen Saxon on November 29, 1944 with dramatic results.
- The Pott shunt and the Waterson procedure are other shunt procedures which were developed for the same purpose.
- Waterson shunt: Shunt between right pulmonary artery and ascending aorta.
- Potts shunt: Shunt between left pulmonary artery and descending aorta.
- The technique has been modified and is usually performed using a Gortex tube to create the connection.
- Currently, Blalock-Thomas-Taussig shunts are not normally performed on infants with TOF except for some conditions like-
- Severe variants such as tetralogy of Fallot with pulmonary atresia
- Premature babies
- Coronary artery origin anomalies
- The Blalock-Taussig procedure was the only surgical treatment until the first total repair was performed in 1954.
- They are usually performed through lateral thoracotomy.
Total Surgical Repair
- The total repair was performed by C. Walton Lillehei at the University of Minnesota in 1954 on a 10-month boy.
- Total repair initially carried a high mortality risk which has consistently improved over the years.
- Surgery is now often carried out in infants 1 year of age or younger with a <5% perioperative mortality.
- The surgery generally involves
- Making incisions into the heart muscle, relieving the right ventricular outflow tract stenosis by careful resection of muscle
- Repairing the VSD using a Gore-Tex or Dacron patch or a homograft.
- Additional reparative or reconstructive work may be done on patients as required by their particular anatomy.
- The repair could be done by either of the approaches i.e.transatrial or transpulmonary
- Patients who have undergone "total" repair of tetralogy of Fallot often have good to excellent cardiac function after the operation with some to no exercise intolerance and have the potential to lead normal lives. Surgical success and long-term outcome greatly depends on the particular anatomy of the patient and the surgeon's skill and experience with this type of repair.
- Pulmonary valve should be replaced before right ventricle dysfunction occurs.
First stage — First stage of surgery is performed in the neonatal period. The goals of the initial palliation are to ensure that blood exiting the right atrium (RA) is unimpeded, provides adequate pulmonary blood flow, protects the pulmonary artery bed from high pressures that could result in higher risk for subsequent operations, and ensures unobstructed flow from the left ventricle (LV) to the aorta. Choices for intervention are dependent on the anatomic variants as follows (table 1):
●TV atresia with normally related great arteries (type I):
•With diminished pulmonary blood flow, the initial surgery soon after birth aims to restore a reliable source of pulmonary blood flow with a modified Blalock-Taussig shunt (shunt from the innominate artery into the central pulmonary artery) (figure 4).
•In the presence of unobstructed pulmonary blood flow (type Ic), a pulmonary artery band may be placed in early infancy to restrict the amount of pulmonary blood flow and protect the pulmonary bed from high systemic pressures. As mentioned above, the vast majority of ventricular septal defects (VSDs) decrease in size over time and restrict pulmonary blood flow. A pulmonary artery band, therefore, may not be required in all patients who have unobstructed pulmonary flow at birth through a VSD, and could be restricted to patients who are symptomatic despite maximal medical therapy for pulmonary congestion/heart failure. Furthermore, a pulmonary artery band may stimulate myocardial hypertrophy that may more rapidly reduce the size of the VSD.
•Rarely, the degree of restriction to pulmonary blood flow is enough to maintain adequate oxygenation without pulmonary overcirculation and heart failure. These patients may not require surgery in the neonatal period and can be taken directly to the second stage of palliation.
●TV atresia with transposition of great arteries (type II):
•In the presence of significant subaortic obstruction with a restrictive VSD, enlargement of the VSD or a Damus-Kaye-Stansel anastomosis (anastomosis between the main pulmonary artery and ascending aorta) with a modified Blalock-Taussig shunt is the initial surgery of choice.
•If an isolated coarctation is present, it should be relieved and a pulmonary artery band may be considered to restrict pulmonary blood flow.
•Similar to type I lesions, in a few cases, the size of the VSD is large enough to maintain systemic output, in which case a pulmonary artery band alone may be adequate.
Second stage — The second palliative procedure for both type I and type II lesions is a cavopulmonary anastomosis (Glenn procedure). This stage of palliation is typically performed at three to six months of life when infants experience progressive cyanosis as they begin to outgrow their neonatal shunt. This surgery involves removal of the original shunt, and direct anastomosis of the superior vena cava to the right pulmonary artery. The Glenn procedure relies on passive venous drainage from the superior vena cava directly into the pulmonary artery. However, there is persistent systemic desaturation due to continued inferior vena cava flow into the RA. In a case series of 557 patients who underwent second stage palliation for single ventricle anatomy from 1998 to 2010, the overall mortality rate was low (4.7 percent) and there were no deaths in the 12 percent of patients who had TV atresia [25]
- Medical management of patients with Ebstein’s anomaly consists of supportive care such as:
- Control of the heart rhythm with antiarrhythmic drugs
- Inotropic agents and diuretics for heart failure
- Anticoagulation in patients with atrial fibrillation and paradoxical embolization Tricuspid valve repair is indicated in patients in which there is symptoms or deteriorating exercise capacity, cyanosis (oxygen saturation less than 90%), paradoxical embolism, progressive cardiomegaly on chest x-ray or progressive right ventricular dilation or reduction of right ventricular systolic function. When possible, repair is favored over replacement.
Antiarrhythmics[edit | edit source]
Some Ebstein's anomaly patients present with an (antidromic) AV nodal reentrant tachycardia with associated pre-excitation. Among these patients, the preferred pharmacological treatment agent is procainamide. Since AV-blockade may promote conduction over the accessory pathway, drugs such as beta blockers, calcium channel blockers and digoxin are contraindicated.
If there is atrial fibrillation with pre-excitation, treatment options include procainamide, flecainide, propafenone, dofetilide and ibutilide since these medications slow conduction in the accessory pathwaycausing the tachycardia and should be administered before considering electrical cardioversion. Intravenous amiodarone may also convert atrial fibrillation and/or slow the ventricular response.
Anticoagulation[edit | edit source]
Warfarin is recommended for patients with Ebstein’s anomaly with a history of paradoxical embolus or atrial fibrillation.
- Pulmonary atresia: Preliminary treatment is cardiac catheterization to evaluate the defect or defects of the heart; this procedure is much more invasive. Ultimately, however, the patient will need to have a series of surgeries to improve the blood flow permanently. The type of surgery recommended depends on the size of the right ventricle and the pulmonary artery. If they are normal in size and the right ventricle is able to pump blood, open heart surgery can be performed to make blood flow through the heart in a normal pattern. If the right ventricle is small and unable to act as a pump, doctors may perform another type of operation called the Fontan procedure. In this two-stage procedure, the right atrium is disconnected from the pulmonary circulation. The systemic venous return goes directly to the lungs, by-passing the heart. The first surgery will likely be performed shortly after birth. A shunt can be created between the aorta and the pulmonary artery to help increase blood flow to the lungs. As the child grows, so does the heart and the shunt may need revised in order to meet the body's requirements.
A cardiac catheterization procedure can be used as a diagnostic procedure, as well as initial treatment procedure as balloon atrial septostomy to improve mixing oxygenated blood and unoxygenated blood between the right and left atria.
Atrial Septostomy: a special catheter with a balloon in the tip is used to create an opening in the atrial septum. The catheter is guided through the foramen ovale to the left atrium (LA). Once the ballon is in the LA is inflated and then pulled back opening a bigger hole between the right atrium and the LA to mix blood.
If the hospital does not have a catheterization lab with skill physician to perform the ballon atrial septostomy, an intravenous medication called prostaglandin is administered to keep the ductus arteriousus from closing.
Palliative interventions
- Cardiac catheterization
- Rashkind balloon atrial septostomy
- Balloon angioplasty
- Endovascular stenting
- Angiography
Cardiac catheterization is a minimally invasive procedure which provides a means of performing a number of other procedures.
- A balloon atrial septostomy is performed with a balloon catheter, which is inserted into a foramen ovale, PFO, or ASD and inflated to enlarge the opening in the atrial septum; this creates a shunt which allows a larger amount of red blood to enter the systemic circulation.
- Angioplasty also requires a balloon catheter, which is used to stretch open a stenotic vessel; this relieves restricted blood flow, which could otherwise lead to CHF.
- An endovascular stent is sometimes placed in a stenotic vessel immediately following a balloon angioplasty to maintain the widened passage.
- Angiography involves using the catheter to release a contrast medium into the chambers and/or vessels of the heart; this process facilitates examining the flow of blood through the chambers during an echocardiogram, or shows the vessels clearly on a chest x-ray, MRI, or CT scan - this is of particular importance, as the coronary arteries must be carefully examined and "mapped out" prior to the corrective surgery.
It is commonplace for any of these palliations to be performed on a TGA patient.
Moderate
- Left anterior thoracotomy
- Isolated pulmonary artery banding (PAB)
- Left lateral thoracotomy
- PAB (when coarctation or aortic arch repair also required)
- Right lateral thoracotomy
- Blalock-Hanlon atrial septectomy
Each of these procedures are performed through an incision between the ribs and visualized by echocardiogram; these are far less common than heart cath procedures.
Pulmonary artery banding is used in a small number of cases of d-TGA, usually when the corrective surgery needs to be delayed, to create an artificial stenosis in order to control pulmonary blood pressure; PAB involves placing a band around the pulmonary trunk, this band can then be quickly and easily adjusted when necessary.
An atrial septectomy is the surgical removal of the atrial septum; this is performed when a foramen ovale, PFO, or ASD are not present and additional shunting is required to raise the oxygen saturation of the blood.
Major
- Median sternotomy
- PAB (when intracardiac procedures also required)
- Concomitant atrial septectomy
In recent years, it is quite rare for palliative procedures to be done via median sternotomy. However, if a sternotomy is required for a different procedure, in most cases all procedures that are immediately required will be performed at the same time.
Surgery should be performed as soon as possible in the patients of total anomalous pulmonary venous connection. The surgical procedure varies depending upon the anatomy of the TAPVC lesion.
- Supracardiac and infracardiac TAPVC: Connection is created between the pulmonary veins and the left atrium. The vertical vein is tied up so that the abnormal blood flow could be prevented.
- Pulmonary veins directly connected to the superiorvenacava: An intracardiac baffle is created that helps in transfer of blood from the right atrium, through atrial septum into the left atrium.
- Intracardiac (pulmonary vein connected to the coronary sinus): Coronary sinus is incised and connected to left atrium.
- Intracardiac (pulmonary vein opening directly into the right atrium): A interatrial connection is made and the blood is redirected from right atrium to left atrium.
- Coarctation of aorta
Late Presentation
Late presenters usually have hypertension. Beta blocker is the treatment of choice for hypertension in these patients both pre and post operatively.
Preoperative
- Beta blockers are the treatment of choice.
- Caution should be taken as too much control of hypertension in upper limb can cause hypotension in lower limbs.
- Surgical treatment of the lesion should not be delayed for the correction of hypertension.
Postoperative
- Immediate post operative hypertension - use short-term vasodilators for e.g. sodium nitroprusside, or intravenous beta-blockers like esmolol.
- Long-term antihypertensive post surgery
- Monotherapy with beta-blockers
- ACE inhibitors or angiotensin II antagonists may be added if hypertension continues with beta-blocker monotherapy.
Surgical Techniques
- The choice of technique depends on the patient's age at presentation, size, associated abnormalities, and anatomy of the coarctation.
- Surgical approach - median sternotomy is preferred over left lateral thoracotomy, in complex arch repairs.
- Subclavian flap aortoplasty is found to be the most commonly performed followed by resection in end-to-end anastomosis, patch aortoplasty, and bypass graft when the surgery is done during infancy. Whereas, in children and adolescent undergoing coarctation repair end-to-end anastomosis is commonest followed patch aortoplasty and subclavian flap aortoplasty.
- Patch aortoplasty are less frequently used these days because of concerns regarding the development of aortic aneurysm at the site of surgery.
- Available Techniques:
- Resection and end-to-end anastomosis
- Patch aortoplasty
- Left subclavian flap aortoplasty
- Tubular bypass grafts
- Combination techniques
Indications for Surgery
- There is a lack of consensus for the indications and the time for surgery. Some groups of surgeon consider balloon angioplasty and stenting as the initial approach and reserving surgery for more complicated conditions or treatment failures. Whereas, others consider surgical repair as the first line of therapy.
- Surgery is the first choice in aortic coarctations involving:
- Long length of aorta
- Severe coarctations causing almost complete or complete obliteration of the aortic lumen.
- Associated with other cardiac defects for e.g. large patent ductus arteriosus, ventricular septal defect.
- If surgical intervention is not available, treatment is mostly palliative
- Anticoagulants
- Pulmonary vasodilators such as bosentan
- PGE 5 inhibitor
- Prostacyclin may improve pulmonary artery pressure and may improve length of life
- Antibiotic prophylaxis to prevent endocarditis
- Phlebotomy to treat polycythemia
- Maintaining proper fluid balance
- These measures can prolong lifespan and improve quality of life