Coarctations vary in severity. When stenosis is localized, the lumen must be reduced in cross-sectional area by more than about 50% before there is a hemodynamically important pressure gradient across it, but longer tubular coarctations may be hemodynamically important with lesser narrowing. Thirty-three percent of autopsy specimens (patients aged 2 years to adulthood) examined prior to the era in which operation was available show moderate luminal narrowing, 42% severe (pinhole) stenosis, and 25% luminal atresia. ^, Occasionally, the adult aorta may be redundant and severely kinked opposite the ligamentum arteriosum, without any pressure gradient; this is called a pseudocoarctation.

The localized morphology of classic coarctation is a shelf, projection, or infolding of the aortic media into the lumen. It is most prominent in the portion of the circumference opposite the ductus arteriosus (the posterior and leftward wall). This inward projection is present also on anterior and posterior walls but absent on the ductal side (inferior or rightward wall). The shelf is usually marked externally by a localized indentation or waisting of the left aortic wall as if a string had been placed around it, pulling the aorta toward the ductus ^, ( Figs. 40.1 and 40.2 ). External narrowing may be absent in the young infant. The aorta beyond the narrowing usually shows poststenotic dilation, and paradoxically the wall beyond the stricture is usually thicker than that just proximal to it where the pressure is higher. The localized shelf or curtain of media and intima lies adjacent to the ductus arteriosus in utero and to the ligamentum arteriosum if the ductus closes. The shelf may be preductal or postductal but is usually periductal. Hutchins pointed out that the histologic features of this aortic media infolding are identical to those seen at a branch point of the normal aorta.

Autopsy specimen from 6-week-old girl showing periductal coarctation caused by localized shelf with typical external deformity of aorta at site of narrowing (arrow) . Asc Ao, Ascending aorta; Desc Ao, descending aorta; LSCA, left subclavian artery; PDA, patent ductus arteriosus; PT, pulmonary trunk.

Cineangiogram in left anterior oblique view with injection into left ventricle, showing severe coarctation caused by localized shelf opposite an obliterated ductus arteriosus in a 5-day-old neonate. No other cardiovascular anomaly was demonstrated. Note marked angulation of aorta toward mediastinum.

In addition to infolding of aortic media, there is usually a localized ridge of intimal hypertrophy (intimal veil) that extends the shelf circumferentially and further narrows the lumen. This, and perhaps other portions of the coarctation area, consists of ductal tissue. ^, It forms a sling that completely surrounds the periductal aorta, ^, which may progressively proliferate after birth and cause restenosis after repair of coarctation in neonates and young infants. It is well documented that use of PGE ₁ can result in symptomatic relief of a critical coarctation in some young infants by relaxing the coarctation site without reopening the ductus. ^,

Rodbard has presented experimental and theoretical evidence that lowering of lateral pressure on the aortic wall secondary to the increase in velocity that occurs across a site of narrowing (according to the Bernoulli principle) allows the intimal cells to multiply until probe patency is reached. ^, Resistance to flow across this stenosis then lowers the velocity so that ingrowth usually stops.

Rudolph and colleagues postulated that prevalence and type of coarctation are related to fetal flow patterns through the ductus and aorta. These investigators have shown that flow through that portion of the arch between origins of the left common carotid and left subclavian arteries in the normal fetal lamb is approximately half that across the ductus, explaining the normally smaller diameter of the arch compared with the ascending and descending aorta in the normal human newborn. A localized shelf opposite the ductus may result from a reorientation of the angle at which the ductus meets the aorta, which results in abnormal fetal flow patterns in some types of cardiac anomalies. The tendency for a shelf to develop is present when ductal flow is increased more than usual relative to isthmus flow; for example, with a ventricular septal defect (VSD). ^, However, intrauterine events that account for the relatively frequent association of coarctation with lesions that produce left-to-right shunts postpartum are not fully identified.

Coarctation, as well as isthmus hypoplasia, is more common than usual when ascending aorta flow is diminished during fetal life (and ductal flow is relatively increased) by lesions such as aortic stenosis or atresia (see Chapters 50 and 51 ), and mitral stenosis or regurgitation (see Chapter 49 ). ^, Conversely, coarctation is rare as the size of the isthmus is increased when pulmonary flow and thus right-to-left ductal flow is decreased by lesions such as pulmonary stenosis or atresia, tetralogy of Fallot, and tricuspid atresia. ^, Coarctation is uncommon when the aortic arch is right sided, presumably because of alteration of ductal and isthmus flow patterns in this situation. ^,

Narrowing of the isthmus —the segment of aorta between a discrete coarctation and the left subclavian artery—commonly exists with coarctation. Narrowing of the distal aortic arch between the left subclavian and left common carotid arteries also coexists commonly, particularly in neonates and infants ( Fig. 40.3 ). This narrowing appears in some cases to be a transient finding related to prenatal flow pattern (excessive ductal flow extending proximally in the aorta and out the left subclavian artery), which reduces flow in the distal aortic arch between the left subclavian and left common carotid arteries and allows this segment to narrow. ^{, ,} This view leads to the inference that surgical enlargement of the distal arch at the time of coarctation repair could be in some cases unnecessary because it will, in any event, gradually enlarge after the coarctation is repaired (see “ Indications for Operation ” later in this section). Others believe that the narrowing in this area is a coexisting congenital anomaly and that the narrow area must be widened surgically at the time of coarctation repair. Whether isolated distal aortic arch narrowing exists as a congenital anomaly in the absence of localized coarctation and results in a pressure gradient is arguable. ^, The Congenital Heart Surgery Nomenclature and Database Project categorized patients with coarctation of the aorta into three groups: Coarctation/hypoplastic aortic arch alone, Coarctation with a VSD, and Coarctation with other complex intracardiac anomalies. This categorization has been helpful for stratifying results of surgical repair.

Autopsy specimen from 5-day-old neonate with coarctation, demonstrating tubular hypoplasia of aortic arch between left common carotid artery (LCC) and patent ductus arteriosus (PDA) . Large left vertebral artery arises separately from arch proximal to left subclavian artery (LSCA) . This neonate also had perimembranous and muscular ventricular septal defects and mild mitral valve hypoplasia. Asc Ao, Ascending aorta; Desc Ao, descending aorta; PT, pulmonary trunk; RCC, right common carotid; RSC, right subclavian artery.

Although coarctation itself, as well as dimensions of adjacent portions of the aorta, has received considerable attention through the years, only in recent years has evidence emerged to indicate that:

• •

  The wall of the entire aorta proximal to the coarctation is abnormal.

• •

  The abnormalities extend out to all major arteries supplied by the aorta proximal to the coarctation.

• •

  These abnormalities may result from in utero development. ^,

Coarctation has been documented by fetal echocardiography in utero as early as 21 weeks of gestation, but it likely exists much earlier. Hypoplasia of the isthmus and, in some patients at least, the distal aortic arch develops during intrauterine development. ^, It is hypothesized that either the coarctation was present very early in development and the hypoplasia is secondary, or the hypoplasia is related to a primary aortic wall abnormality rather than to the coarctation. Or, the hypoplasia and coarctation are a result of altered patterns of blood flow caused by intracardiac abnormalities that lead to decreased flow to the arch and increased flow to the ductus during fetal development.

Degenerative changes occur in the peripheral arterial vasculature proximal to the coarctation, and these changes persist after coarctation repair and can be identified in children. Surrogate markers of arteriosclerosis, such as impaired flow-mediated vasodilation and increased intima media thickness, were apparent in a study group with a mean age of 12 years.

Collateral circulation between the aorta proximal to the coarctation and that distal to it is one of the striking features of coarctation. When well developed, it is responsible for some of the classic signs of the malformation, such as parascapular pulsations and rib notching. It is usually present to some extent in newborns but increases in size and extensiveness as the patient ages ( Fig. 40.4 ).

Major collateral channels in coarctation of the aorta.

(From Edwards JE, Clagett OT, Drake RL, Christensen NA. The collateral circulation in coarctation of the aorta. Mayo Clin Proc . 1948;23:333.)

Inflow into the collateral circulation is widespread, but is primarily from branches of both subclavian arteries, particularly internal thoracic, vertebral, costocervical, and thyrocervical trunks. Outflow from the collateral system is primarily into the upper descending thoracic aorta. The largest vessels participating in this outflow are usually the first two pairs of intercostal arteries distal to the coarctation. These are the third and fourth intercostal arteries, and they are greatly enlarged by the large reversed flow (outflow from collateral circulation). This reversed flow into the aorta can be documented by magnetic resonance imaging (MRI) and has been demonstrated at operation by directional Doppler velocity detector probes. Flow returns to a normal direction immediately after coarctation repair. Only the intercostals carrying this large reversed flow are sufficiently enlarged to produce rib notching, which explains lack of notching of the first and second ribs, whose intercostals arise above the coarctation. The lower intercostal arteries provide less outflow from the collateral circulation, as do the inferior epigastric artery and other branches of the abdominal aorta.

Collateral circulation and its clinical manifestations are altered by anatomic variations associated with classic coarctation. Associated stenosis at the origin of the left subclavian artery excludes this artery as an important source of inflow into the collateral circulation; thus, rib notching occurs only on the right side. When the right subclavian artery arises as the fourth aortic branch (see “ Morphology ” in Section I of Chapter 39 ) and distal to the coarctation, it does not serve as a source of inflow, and rib notching occurs only on the left side.

Enlarged, tortuous third and fourth intercostal arteries may become aneurysmal, but this is rare before about age 10 years. Resulting thin-walled aneurysms are usually saccular and are most likely to occur at the aortic origin of intercostal arteries. This is a weak point of surgical importance; if an enlarged intercostal artery must be ligated, the ligature should be placed a few millimeters beyond its aortic origin.

The aorta itself may become aneurysmal adjacent to the site of maximal narrowing as a result of hemodynamic effects, aortic dissection, or mycotic aneurysm. This is uncommon in young children. Prevalence of aneurysm is about 10% by the end of the second decade of life, 20% by the end of the third decade, and probably even higher in older patients.

Left ventricular hypertrophy occurring in untreated patients is accompanied by histologic changes in coronary arteries. In young patients, nonarteriosclerotic lesions are conspicuous in the intimal layer. These consist of degenerative and proliferative changes of the elastic fibers and excess collagenous tissue. The media thickens to about twice normal with a rich elastic fiber network and often hyaline changes. Mean total area of the coronary arteries is increased, so they have greater than normal capacity, presumably in response to increased metabolic requirements of the left ventricle. As a result of prolonged hypertension, arteriosclerotic changes are apt to occur more often and at a younger age. In adolescents and young adults, reduced myocardial perfusion reserve is apparent.

In newborn infants, it is common for the “valve” of the foramen ovale to be prolapsed, causing left-to-right shunting. This prolapse often resolves after coarctation repair. A true secundum atrial septal defect (ASD) may also occur with coarctation. Moderate to large ASDs appear to show the same tendency to close when coarctation is present and when it is not. In about 10% of patients with ASD, however, intractable heart failure will develop in infancy following coarctation repair, requiring ASD closure. The best predictor of development of heart failure when ASD coexists with coarctation is small mitral valve diameter, not the size of the ASD itself.

Left ventricular hypertrophy without volume increase is present in most patients with coarctation within a few days of birth. This progresses as the patient ages and may be aggravated by associated cardiac anomalies.

The left ventricular outflow tract (LVOT) may be abnormal in patients with arch obstruction, particularly when a VSD coexists. The left ventricular papillary muscles may be abnormally positioned, typically with a reduced interpapillary distance.

A bicuspid aortic valve is common, although its exact prevalence is uncertain. In two autopsy series, it was 46% and 27%, with an additional 6% and 7%, respectively, with congenital valvar stenosis. Tawes and colleagues report that among 250 living children with long-term follow-up, 32 (13%) had clinical evidence of aortic valve disease (mainly stenosis but also regurgitation). When aortic regurgitation appears in coarctation, it is usually based on a bicuspid aortic valve combined with persistent hypertension. Bicuspid aortic valve is known to be associated with dilation of the ascending aorta. In one study, presence of coarctation in this setting was not associated with increased magnitude or rate of ascending aortic dilation. Another study indicates that patients with coarctation and bicuspid aortic valve have greater aortic root dilation than those with coarctation and tricuspid aortic valves. ^, In the presurgical era, aortic dissection was noted to occur in 19% of coarctation patients without bicuspid aortic valve but in 50% of those with bicuspid aortic valve. ^,

Coarctation and berry-type intracranial aneurysm coexist in some patients. Some instances of sudden death in untreated as well as treated coarctation are from rupture of the intracranial aneurysm. That coarctation, bicuspid aortic valve, and intracranial aneurysm are associated leads to the inference that coarctation is only one manifestation of a diffuse arteriopathy.

Coarctation (with or without a patent ductus arteriosus, and with or without hypoplasia of the isthmus or distal aortic arch between left common carotid and left subclavian arteries) sometimes coexists with multiple obstructions of the left heart aorta complex and left ventricular hypoplasia known as the Hypoplastic Left Heart Syndrome (see “ Morphogenesis and Morphology ” in Chapter 51 ). This is particularly a problem in symptomatic neonates and infants. These anomalies include:

• •

  Ascending aorta hypoplasia

• •

  Supravalvar, valvar, subvalvar, and anular aortic stenosis or hypoplasia

• •

  Aortic atresia

• •

  Left ventricular hypoplasia or hypertrophy

• •

  Endocardial fibroelastosis

• •

  Mitral stenosis or hypoplasia with or without a single papillary muscle (parachute mitral valve)

• •

  Supravalvar mitral ring

When these occur in any of a number of possible combinations, they represent the Hypoplastic Left Heart Syndrome if the left heart is unable to adequately sustain the systemic circulation (see Chapter 51 ).

Multiple associated anomalies within the left heart are not unusual even when a functional left heart is present in early infancy. Levine and colleagues have shown that additional left heart obstructive lesions develop late in more than 20% of patients originally diagnosed in early infancy with isolated coarctation. A predictor of these additional anomalies is mitral valve diameter with a z -score less than −1 on the original echocardiogram. A broad spectrum of sizes of important left heart structures can exist without negatively affecting left heart function.

When coarctation first presents in older children and young adults (as it did in the early years of cardiac surgery, but uncommonly now), coexisting cardiac anomalies are uncommon. When it presents in neonates, and to some extent in infants, coexisting cardiac anomalies are common ( Table 40.1 ). These associations are explained by the fact that survival beyond infancy is much less likely when coexisting anomalies are present. Thus, long-term survivors tend to have simple lesions. Because in the current era most coarctations are diagnosed in neonates or infants, it follows that prevalence of associated anomalies found in neonates with coarctation closely approximates true prevalence.

Patent ductus arteriosus is present in almost 100% of neonates and in most infants with a preductal type of coarctation. This is considered part of isolated coarctation rather than an additional anomaly. Tubular hypoplasia of the distal aortic arch is also considered to be part of the anomaly of coarctation rather than an associated anomaly. ASD is not considered as an additional anomaly unless large enough to need closure. This excludes the fairly numerous examples of infants presenting with a left-to-right shunt through a stretched patent foramen ovale that may subsequently close. Anomalous right subclavian artery occurs in about 1% of cases of coarctation and may be proximal or distal to the coarctation. This variation does not appear to affect the collateral circulation that develops in any clinically significant way.

Approximately 82% of individuals born with coarctation have it as an isolated lesion (with or without continuing patency of the ductus arteriosus). About 11% have an important coexisting VSD, and approximately 7% have other important coexisting cardiac anomalies. These prevalences are different from those in patients who become symptomatic during neonatal life or infancy and require early intervention (see Table 40.1 ).

Prevalence of isolated coarctation in patients with an otherwise normal heart appears to be about 40 per 100,000 live births. Persons with pulmonary stenosis or atresia, tetralogy of Fallot, and tricuspid atresia with concordant ventriculoarterial connection have a prevalence of coarctation close to 0 per 100,000. Patients with aortic stenosis and mitral stenosis or regurgitation have a considerably higher prevalence than patients with otherwise normal hearts. Patients with VSD and other lesions such as transposition, double outlet right ventricle, truncus arteriosus, atrioventricular septal defect, and single ventricle who have associated VSD also appear to have a high prevalence of coexisting coarctation. This may relate to altered blood flow patterns within the heart that result in less flow across the aortic isthmus during fetal development.

Severe heart failure in a neonate or infant requires that coarctation be considered, especially when a favorable response to medical treatment does not occur promptly. It may be unsuspected in complex lesions when the baby is in extremis, because even when the ductus is closed, a large left-to-right shunt proximal to the aorta can decrease manifestation of hypertension in the arms. Severe proximal obstructing lesions (aortic or mitral stenosis) can have a similar effect. Control of heart failure and tachycardia in these situations frequently unmask differential pressures in upper and lower extremities as cardiac output improves.

Signs and symptoms of coarctation presenting in the neonate are those of heart failure. After a variable period of well-being, tachypnea, feeding problems, and sweating develop. On examination, there is a gallop rhythm and a systolic murmur along the left sternal edge and usually posteriorly over the coarctation site. Femoral pulses are absent or reduced in volume and delayed compared with radial or brachial pulses, although in small, sick infants with tachycardia, pulse delay may be difficult to detect. Blood pressure is higher in the arms than in the legs (by >20 mmHg). Delay in onset of heart failure is probably related, at least in isolated coarctation, to the variable time it takes for the ductus to close. Ductal closure usually commences at the pulmonary end, and generally it is not until the aortic end closes that the periductal aortic shelf produces severe obstruction (see “ Morphology ” earlier in this section). ^, Thus, femoral pulses can be normal at birth but absent at 1 week.

When the ductus arteriosus remains widely patent and a severe coarctation lies proximal to it (preductal coarctation), there may be a right-to-left shunt into the descending aorta and, classically, cyanosis of the toes and sometimes the left hand while the right hand and lips remain pink (differential cyanosis). Femoral pulses are normal, and there is no ductal murmur. In fact, differential cyanosis is uncommon, either because flow through the coarctation is large or because Po ₂ of the pulmonary artery blood is high from an additional intracardiac shunt through a VSD, an interatrial communication, or both. Moreover, despite presence of a severe coarctation proximal to a patent ductus arteriosus, systemic vascular resistance in the lower compartment usually exceeds pulmonary vascular resistance, so the ductal shunt is left-to-right or bidirectional.

In infancy, hypertension may be present but is seldom severe, and a collateral circulation is not palpable, although it is usually present angiographically ( Fig. 40.5 ). Marked cardiomegaly is almost invariable on chest radiograph. The electrocardiogram (ECG) usually shows right ventricular hypertrophy in the first few months of life, even with isolated coarctation. About two-thirds of infants operated on in the first year of life have right ventricular hypertrophy or combined hypertrophy, and fewer than 25% have pure left ventricular hypertrophy. ^,

Cineangiograms in left anterior oblique view with injection into left ventricle of a severe coarctation 5 mm in length in a 7-week-old infant without other associated anomalies. (A) Aortic arch and branches are outlined proximal to coarctation, but distal aorta is not opacified. Collateral vessels are visible. (B) Dense collateral network is visible in this later frame, with contrast in descending aorta below coarctation. (C) Descending aorta is well outlined, most of its filling coming from collaterals, although a tiny lumen about 5 mm long could be identified connecting the two ends. LCA, Left coronary artery.

Left-to-right shunt through a stretched patent foramen ovale is common in infants with severe coarctation in heart failure. When heart failure disappears, so does the atrial shunt. Congenital aortic stenosis may not be evident clinically (or by catheter withdrawal pressure differential) in infancy, and yet it may be severe enough to require surgical relief at age 2 to 5 years, particularly when it is subvalvar (see Section II in Chapter 50 ).

Almost all patients who first present at age 1 to 14 years are asymptomatic unless they have important associated anomalies. Tawes and colleagues noted that children with associated anomalies may present in heart failure up to age 3 years, and Patel and colleagues noted heart failure in 7 of 65 children (11%) age 1 to 14 years. Subarachnoid hemorrhage from rupture of a berry aneurysm occurs occasionally but is rare in children younger than 7 years, and spontaneous paresis or paraplegia caused by dilated intercostal arteries compressing the anterior spinal artery or by epidural hemorrhage is even less common. Hypertension occurs in almost 90% of patients.

The chest radiograph shows cardiomegaly in 33% and rib notching in about 15% ( Fig. 40.6 ), but this feature does not occur before age 3 years. ^, ECG shows predominantly left ventricular hypertrophy, with right ventricular hypertrophy present only when there is pulmonary hypertension with elevated pulmonary vascular resistance. ECG is normal in about one-third of children.

Portion of chest radiograph showing severe rib notching in patient with coarctation of the aorta. Note that changes are not present in first two ribs and are typically less severe below the fifth rib.

Many adolescent and young adult patients remain asymptomatic and are diagnosed at routine examination because femoral pulses are noted to be absent or reduced and delayed in the presence of a cardiac murmur, hypertension, or an abnormal chest radiograph. Hypertension is common and more severe than in younger patients, and heart failure may occur after about age 30 years. Heart failure is preceded by effort dyspnea, cardiomegaly, and important left ventricular hypertrophy on ECG. Headache, nose bleeds, fatigue, and calf claudication occasionally occur. Collaterals are usually palpable or audible posteriorly. Radiographic findings include a “figure-3” sign in the left upper mediastinal shadow ( Fig. 40.7 ) and, almost always, rib notching (absence of rib notching in the right chest suggests an anomalous origin of the right subclavian artery and in the left chest a stenosis of the left subclavian artery origin).

Radiographic studies in patient with coarctation, demonstrating classic figure-3 sign present in some patients with coarctation of the aorta. (A) Chest radiograph. Upper convexity of sign is formed by the aortic isthmus and left subclavian artery, lower convexity by the upper descending aorta at site of poststenotic dilation. (B) Barium esophagogram. Note how the two shadows overlap. Isthmus and descending aorta produce upper and lower indentations on leftward margin of barium-filled esophagus.

There is an association between Turner syndrome and von Recklinghausen disease and coarctation. ^, Rarely, patients with coarctation have Noonan syndrome or congenital rubella.

Two-dimensional echocardiography can visualize coarctation in neonates and small infants ( Fig. 40.8 ) and is usually the definitive study. Associated intracardiac defects can also be defined in detail. Severity of coarctation can often be assessed by characterizing intracardiac and great artery blood flow patterns using color Doppler signaling. Fetal echocardiographic measurements of the z value of the aortic isthmus and the isthmus-to-ductus ratio are sensitive indicators of postnatal coarctation. Outside infancy, echocardiography may still be helpful but is usually not definitive. In moderate or mild coarctation, presence of an open ductus may obscure a coarctation at echocardiographic examination. This is due partly to altered blood flow patterns associated with the patent ductus, but more importantly to the fact that the coarctation itself may evolve as the ductus closes.

Echocardiographic images of neonatal aortic coarctation. (A) Parasternal view showing small-diameter ascending aorta with origins of brachiocephalic and left carotid arteries, severe hypoplasia of distal aortic arch between left carotid and subclavian arteries, discrete coarctation, and descending aorta. (B) Color imaging showing discrete narrowing at coarctation site. (C) Image details hypoplasia of distal arch and isthmus, and a large ductus arteriosus entering descending aorta. A discrete coarctation, which was also present in this case, is not seen well in this image. AA, Ascending aorta; AI, aortic isthmus; BA, brachiocephalic artery; CO, coarctation; DA, distal aortic arch; DES, descending aorta; LCA, left carotid artery; LSCA, left subclavian artery; PDA, patent ductus arteriosus.

MRI and computed tomography (CT) are currently the imaging modalities of choice for coarctation in patients beyond infancy. ^, Excellent detailed imaging of pertinent vascular structures can be obtained, often exceeding the detail seen with aortography ( Fig. 40.9 ). Three-dimensional rendering can be particularly informative ( Fig. 40.10 ). Postsurgical changes also can be defined in detail ( Fig. 40.11 ). CT may offer higher resolution anatomic imaging, though MRI may offer hemodynamic data that may be particularly useful in older patients with well-developed collaterals or in patients with restenosis in whom there may be little or no gradient across the coarctation site. Assessment of flow in the collaterals directly, and quantitation of the flow increase in the aorta at the diaphragm compared with the flow in the upper aorta near the coarctation (as a measure of collateral flow), can be more accurate in determining the significance of the coarctation or recoarctation. ^, MRI does not utilize iodinating contrast but may require general anesthesia in younger pediatric patients. Cross-sectional imaging (MRI and CT) can also yield data for virtual and physical three-dimensional rendering.

Magnetic resonance imaging of coarctation. (A) Lateral projection (using contrast-enhanced imaging and cardiac gating) of native coarctation in 20-year-old man. Isthmic hypoplasia and collateral vessels are also present. (B) Lateral projection (using T1-weighted imaging) of recurrent coarctation in 35-year-old woman. (C) Three-dimensional rendering of patient shown in B. (D) Lateral projection (using contrast-enhanced magnetic resonance imaging) of 40-year-old man with recurrent obstruction following childhood creation of left subclavian artery-to-descending aortic synthetic graft bypass of aortic coarctation. (E) Three-dimensional rendering of recurrent obstruction shown in D. AI, Aortic isthmus; CO, coarctation; CV, collateral vessels; LSCA, left subclavian artery; SCB, subclavian-to-descending aortic bypass.

Volume-rendered computed tomography angiogram of a 5-year-old girl. Ascending aorta is connected to two proximal aortic arches developed from the fourth branchial arch and the fifth branchial arch. The fifth arch is in continuity with the descending aorta, but with no detectable lumen. 4, Fourth branchial arch; 5, fifth branchial arch; AA, ascending aorta; DA, descending aorta.

Magnetic resonance (MRA) and computed tomographic (CTA) angiograms of previously repaired coarctation. (A) Maximal-intensity projection image from contrast-enhanced MRA of a 25-year-old man who had a remote childhood repair of coarctation. Image demonstrates an eccentric filling defect (arrow) that nearly occludes repaired segment of the aorta. It may represent thrombus and fibrous scar. (B) Maximal-intensity projection image from cardiac gated CTA of an 18-year-old man who had a focal periductal coarctation distended by a stent. (C) Maximal-intensity projection image from contrast-enhanced MRA of a 27-year-old woman who developed an aneurysm at site of repaired coarctation.

Cardiac catheterization and aortography , once the standard for diagnosis in older patients, now play a secondary role and are used mainly when hemodynamic data are important in determining management of the patient. A withdrawal gradient is present at rest across the coarctation, and in borderline cases, measurement of cardiac output and gradient during exercise helps assess severity. Severity of the coarctation can be better assessed on aortography than by catheter withdrawal pressures, mainly because collateral flow may increase the pressure in the aorta distal to the coarctation. Aortography also reveals any hypoplasia of the isthmus or arch, arrangement of the aortic arch branches, degree of collateral circulation, and presence of an aneurysm. Intracardiac hemodynamics can provide important information when there is concern about valve function, myocardial function, or pulmonary hypertension.

This category includes patients with or without associated patent ductus arteriosus.

Most infants born with a large VSD and coarctation develop severe heart failure in the first month. By contrast, presentation so early is uncommon in patients with isolated large VSD (see “ Natural History ” in Section I of Chapter 33 ). Unless the VSD rapidly diminishes in size, most of these babies die within a few months without surgical treatment. However, in many the VSD rapidly becomes small, and the natural history then becomes essentially that of isolated coarctation.

The combination of coarctation with other major cardiac anomalies nearly always produces severe heart failure during the early weeks of life. Without surgical treatment, from 80% to 100% of such babies die in their first year of life. ^{, ,}

All reported series show a high proportion of associated cardiovascular anomalies in patients with coarctation presenting in infancy ^{, , ,} (see Table 40.1 ). In such infants, isthmus and arch hypoplasia is almost constant as a consequence of disturbed fetal blood flow patterns (see “ Morphology ” earlier in this section). In many of these infants, particularly those with complex and severe intracardiac anomalies, the natural history is primarily that of the associated anomaly. However, associated severe coarctation undoubtedly precipitates early heart failure.

Some form of this operation is currently the preferred technique for young patients. Once the coarctation is resected, there are various options for reconstruction, each of which is described in this section.

Neonates and infants.

When the coarctation is well beyond the origin of the left subclavian artery , the proximal clamp may be placed across the aorta to include the origin of the left subclavian artery. The distal clamp is placed on the aorta between the second and fourth set of intercostal arteries and can be used to simply occlude the first sets without dividing them. The ligamentum arteriosum or ductus arteriosus, which has been tied (ideally with a suture ligature) at its pulmonary end, is transected at its aortic insertion. The aorta is transected proximal to the coarctation at a level that ensures removal of any narrowed portion of the isthmus as well as the coarctation ( Fig. 40.13 A). Similar transection of the aorta is made beyond the coarctation, where the aortic diameter is usually ample. The suture line is made with a continuous simple suture of 6-0 or 7-0 absorbable monofilament suture, sewing “from within” for the posterior wall ( Fig. 40.13 B). After the posterior row of sutures has been placed, the ends of the aorta are approximated by the assistant and the sutures are gently pulled up snugly. The remainder of the anastomosis is completed by suturing the anterior wall using the other end ( Fig. 40.13 C). Alternatively, interrupted sutures may be used for the anterior wall anastomosis. Finally, the clamps are removed as described under “Immediate Postrepair Management” and the operation completed similarly ( Fig. 40.13 D).

Resection and end-to-end anastomosis for repair of coarctation. (A) With patient in right lateral decubitus position, a curving incision is made around the angle of the scapula, the chest opened, and stay sutures placed on the edges of the mediastinal pleura and held under tension to aid exposure (as shown in Fig. 40.12 a and b but eliminated here for simplicity). After sharply dissecting out the coarctation and contiguous structures, tapes (or elastic loops in neonates and small infants) are placed around aorta just above and below coarctation. Traction on tapes elevates aorta anteriorly or posteriorly to provide exposure that facilitates dissection. Dashed lines show levels of aortic transection above and below coarctation site. (B) Ductus arteriosus (or ligamentum arteriosum) has been ligated and divided, and small bulldog clamps (clips) have been placed on third and fourth pairs of intercostal arteries. In neonates and small infants, the distal clamp can be angled to include the first sets of intercostal arteries without using separate bulldog clamps. Proximal clamp is positioned across aorta and base of subclavian artery to leave ample length for the proximal cuff. Coarctation is excised, getting back to a wide orifice proximally and distally. Running monofilament absorbable suture line is begun at far end of the circumference and progresses along posterior aspect of anastomosis. (C) Aortic ends have been approximated, and posterior circumference suture line is completed. Anterior suture line is begun at far end of the circumference (see text). (D) Completed anastomosis is shown after removal of clamps. ICA, Intercostal artery; LCA, left common carotid artery; LPA, left pulmonary artery; LSCA, left subclavian artery; PDA, patent ductus arteriosus.

When the coarctation is near the takeoff of the left subclavian artery , or when the segment between it and the subclavian artery is importantly hypoplastic, proximal transection is begun just beyond the origin of the left subclavian artery.

When the distal portion of the aortic arch between the left common carotid and subclavian arteries is hypoplastic , as it often is in neonates and young infants, the operation may be modified so as to enlarge this area. A proximal clamp is placed occluding the left carotid and the left subclavian artery and part of transverse arch in cases of severe arch hypoplasia, avoiding occlusion of brachiocephalic artery based on the radial arterial line tracing and NIRS monitoring. Dotted lines show direction of the incisions ^, ( Fig. 40.14 A–C). In young patients, end-to-end anastomosis is easily accomplished after extended resection, and the distal transverse arch and aorta proximal to the coarctation are widened by the procedure. Alternatively, (see Fig. 40.15 A), after resecting the discrete coarctation, the isthmus is ligated with a 5-0 polypropylene ligature, and the undersurface of the proximal arch is incised opposite the left carotid artery origin and extended to the point opposite the left subclavian artery origin. The cut end of the descending aorta, trimmed of all ductal tissue, is connected to the incision in the undersurface of the arch with an end-to-side anastomosis using a running suture technique with 6-0 or 7-0 absorbable monofilament suture ( Fig. 40.15 B and C).

Resection and extended end-to-end aortic anastomosis for aortic coarctation with hypoplasia of isthmus and aortic arch. (A) Stay sutures are placed on edges for exposure. It is occasionally necessary to divide one or more intercostal vessels to minimize tension on anastomosis. Ductus arteriosus is sutured and transfixed proximally and distally to aorta and sectioned. A proximal clamp is placed occluding left carotid and left subclavian artery and part of transverse arch in cases of severe arch hypoplasia, avoiding occlusion of brachiocephalic artery based in radial arterial line curve and near-infrared imaging spectroscopy (NIRS) monitoring. Dotted lines show the points of transection and extended incisions to enlarge the narrowed area of the distal arch. (B,C) Coarctation zone is completely removed, and end-to-end anastomosis performed using running 6-0 or 7-0 polypropylene suture.

Resection and end-to-side aortic anastomosis for aortic coarctation with hypoplasia of isthmus and aortic arch. (A) Incision and dissection are similar to that described in Fig. 40.12 . Dashed lines show transection sites on distal aspect of isthmus, ductus arteriosus, and descending aorta, and incision site on undersurface of proximal aortic arch. (B) Proximal aortic clamp is placed on aortic arch to include bases of left subclavian and left carotid arteries, with tip of the clamp angled precisely to extend as far proximally as possible without causing obstruction of flow to brachiocephalic artery. Distal aortic clamp is placed between third and fourth sets of intercostal vessels, and the third set of intercostal vessels is controlled with clips. Aortic isthmus is ligated. Ductus arteriosus is ligated at its pulmonary artery end, and coarctation site, including aortic end of ductus, distal aspect of aortic isthmus, and first portion of descending aorta beyond coarctation site, is completely resected along the lines shown in (A). Incision in undersurface of aortic arch is made such that the length of the incision accommodates entire circumference of the normal aspect of descending aorta. Suture line is begun at far end of the circumference with a running monofilament absorbable suture. (C) Anastomosis is performed essentially identically as described in the end-to-end anastomosis (see Fig. 40.13 ), proceeding along the posterior aspect of the circumference and then the anterior aspect. Completed end-to-side distal aorta to arch anastomosis is shown. BA, Brachiocephalic artery; LCA, left common carotid artery; LSCA, left subclavian artery; PDA, patent ductus arteriosus.

Currently, this technique is most frequently used selectively in neonates when circumstances make resection and reconstruction inappropriate. To begin the subclavian flap aortoplasty, dissection of the subclavian artery is carried distally to expose the branches. It is ligated and divided proximal to all branches, none of which are ligated ( Fig. 40.16 A). In the neonate supported with intravenous PGE _1, the infusion is continued until the ductus is ligated. The ductus arteriosus is gently dissected. A delicate vascular clamp is placed across the aortic arch between the left common carotid and left subclavian arteries, and the ductus is ligated. A second clamp is placed well distal to the coarctation but proximal to the intercostal arteries, allowing space above and below the coarctation for the incision, as shown by the dotted line in Fig. 40.16 A. Uncommonly, it must be placed beyond the third pair of intercostal arteries (the first set beyond the coarctation), which are then controlled with removable metal clips or vessel loops.

Subclavian flap repair for coarctation. Exposure is shown in Fig. 40.12 A and B. (A) Mediastinal pleura has been opened and stay sutures placed on the edges for exposure. After dissection is completed (see text) and after left subclavian artery has been ligated just proximal to vertebral artery, a vascular clamp is placed across aortic arch between left common carotid and left subclavian arteries. The ductus is ligated. Distal aortic clamp is placed on descending aorta and may be positioned proximal to the third set of intercostal arteries, or as far distally as just distal to the fourth set of intercostal arteries (see text). Dashed line indicates proposed aortic incision. (B) Subclavian artery has been divided distally and turned down for the flap. (C) Flap sewn into place and aortic clamps removed (see text). ICA, Intercostal artery; LCA, left common carotid artery; LPA, left pulmonary artery; LSCA, left subclavian artery; PDA, ductus arteriosus; RLN, recurrent laryngeal nerve.

The subclavian artery, before its transection, is split open longitudinally along its posterior margin, carrying this incision across the coarctation into the dilated distal aorta for at least 1 cm. Stay sutures are placed on either side at the level of the coarctation. The subclavian artery is transected just proximal to the ligature. Sharp corners at the end of the opened subclavian artery are trimmed; if the subclavian flap is unusually wide, the lateral edge is trimmed so that its width is about 1.5 times the diameter of the aorta. The turned-down subclavian flap may be tacked to the distal opened aorta using a double-ended 6-0 or 7-0 absorbable monofilament suture, which is then carried proximally as a continuous stitch ( Fig. 40.16 B). Alternatively, the suture line may be started proximally on the medial side and carried just beyond the inferior angle of the aortic incision; another suture line is then started proximally on the lateral side and carried down to the previous one. Absorbable monofilament suture material 6-0 or 7-0 is used. Angles at either end of the turned-down subclavian flap must lie beyond the level of the coarctation, achieving this when necessary by sliding the flap distally in the process of suturing. In this manner, a proper “cobra head” is achieved. Following completion, the aortic clamps are removed ( Fig. 40.16 C).

Subclavian flap aortoplasty can be combined with resection with end-to-end anastomosis if there is concern about the size of the aorta just beyond the subclavian artery. This problem is better managed by resection with extended end-to-end anastomosis or resection with end-to-side anastomosis, as described earlier; however, the combined operation will be briefly described for completeness. After preparing the subclavian artery and placing clamps as for the standard subclavian flap repair, the coarctation area is excised as described for standard end-to-end anastomosis. The proximal and distal aortic segments are reconstructed with an end-to-end anastomosis, with the exception that the posterior wall and anterior wall continuous suture lines are not tied to each other posterolaterally after their completion. Rather, each suture line is tied to itself posterolaterally, leaving a small posterolateral gap. The subclavian artery is split open longitudinally, and incision is extended into the proximal aortic segment, then carried through the small suture line gap onto the distal aortic segment. The subclavian flap is sewn into position as described previously in the standard subclavian flap method, straddling across the end-to-end anastomosis.

When hypoplasia occurs proximal to the left subclavian artery, the usual methods of repair can be unsatisfactory. When the situation is encountered in infants, a reversed subclavian flap aortoplasty may be used. Resection with end-to-side anastomosis as described earlier in this section can be performed with additional modifications. ^,

The reverse subclavian flap combined with end-to-end anastomosis is illustrated in Fig. 40.17 . After usual exposure and dissection, the left common carotid artery and aortic arch between this and the subclavian artery are completely dissected. A side-biting clamp is placed across the aortic arch to include the left carotid, left subclavian artery, and the aortic isthmus. The subclavian artery is ligated and divided distally. The subclavian artery is split down its medial side and the incision extended proximally onto the arch and the origin of the left common carotid artery ( Fig. 40.17 A). The subclavian artery is turned down, in reverse to the classic subclavian flap operation, and sewn into place ( Fig. 40.17 B). The clamp is removed and several minutes are allowed to reperfuse while achieving any necessary hemostais. Arch and distal aortic clamps are then positioned as for a standard end-to-end anastomosis ( Fig. 40.17 C). Alternatively, the end-to-side anastomosis of the descending aorta to the arch, as described earlier in this section under “Resection and Primary Anastomosis,” can be used. In addition, when an anomalous right subclavian artery is present, it can be used in the reconstruction to address arch hypoplasia.

End-to-end anastomosis with reverse subclavian flap for aortic coarctation with isthmic and distal arch hypoplasia. (A) Exposure and dissection is as described in Fig. 40.12 A and B. Dashed line shows incision along left subclavian and left carotid arteries that is necessary to perform reverse subclavian flap. (B) A side-biting vascular clamp is placed across the proximal aortic arch to include base of left carotid, left subclavian arteries, and aortic isthmus. Incision shown by dashed line in (A) is performed, and distal subclavian artery is ligated. Using a monofilament absorbable suture, opened subclavian artery is anastomosed to base of left carotid artery to augment distal aortic arch diameter. Dashed lines show points of transection for subsequent end-to-end anastomosis. (C) Clamp shown in (B) is removed and replaced by arch clamp. Distal aorta is clamped between third and fourth sets of intercostal vessels, and the third set of intercostal vessels is controlled with clips. Ductus arteriosus is ligated and divided, and aortic coarctation resected along dashed lines shown in (B). End-to-end anastomosis is performed in routine fashion (see Fig. 40.13 ).

In older patients, replacement of the coarctation segment with an interposed tube graft may be done when the coarctation is severe, but techniques for aneurysms of the distal portion of the transverse aortic arch are necessary (see “ Replacement of Aortic Arch ” under Technique of Operation in Chapter 23 ). The simpler palliative placement of a bypassing polyester tube graft between the ascending aorta and lower descending thoracic aorta via a right thoracotomy may be used, but is less satisfactory and should be reserved for particularly complex recurrent arch obstructive problems (see “ Special Situations and Controversies ” later in this section for further discussion). ^,

When an aneurysm is present, either in the intercostal arteries (single or multiple) or aorta (see Morphology earlier in this section), resecting the segment of aorta involved along with the coarctation is required, and continuity is reestablished with an interposed tubular polyester graft. This procedure can be hazardous, particularly with regard to hemostatic control of the large intercostal artery feeding into the aneurysm. Pharmacologically induced hypotension is helpful to dissection. Early placement of the proximal aortic clamp and then ligation and division of the ligamentum arteriosum and placement of a clamp across the coarctation itself allows transection of the aorta proximal to the coarctation. Then gentle forward traction on the clamp across the coarctation allows the distal aorta and posteriorly placed intercostal artery aneurysm to be brought into better view for dissection and management.

Postrepair paraplegia is a greater hazard than usual because of the need to sacrifice intercostal arteries (see “ Paraplegia after Aortic Clamping ” under Special Situations and Controversies). Special precautions required for all aneurysm surgery in this area are used (see “ Replacement of Descending Thoracic Aorta ” under Technique of Operation in Chapter 23 ).

Transcatheter interventions for recurrent coarctation are expanding (see “ Balloon Aortoplasty and Stenting for Coarctation ”), but several surgical options exist. The choice is partly determined by morphologic details of the obstruction and partly by surgeon preference. Resection and primary anastomosis, subclavian flap repair with or without resection, patch aortoplasty, and placing an interposition graft can all be considered. Repeat left thoracotomy is feasible in selected cases with discrete obstruction that does not involve the arch; however, most cases require median sternotomy and cardiopulmonary bypass (CPB). Results are usually excellent. ^,

In particularly difficult technical situations in older patients, a bypassing polyester tube graft may be all that is possible. This may be done through a left or right thoracotomy ^, but is conveniently performed in an extra-anatomic fashion through a median sternotomy. The end of a properly prepared polyester tube is anastomosed to the side of the intrapericardial portion of the ascending aorta using a side-biting clamp on the aorta. The tube graft is routed anterior or posterior to the inferior vena cava, and the supradiaphragmatic aorta is exposed through a posterior pericardiotomy. A side-biting clamp is placed on the descending aorta, and the end-to-side anastomosis is performed. This approach is especially useful in adult patients with associated hypoplasia of the aortic arch and in situations when a concomitant cardiac procedure is necessary. Kanter and colleagues have described the use of extra-anatomic aortic bypass via sternotomy for complex recurrent aortic arch obstruction in children.

Aneurysm formation after coarctation repair with patch aortoplasty occurs in 5% to 25% of patients 3 to 18 years following repair. Aneurysm following coarctation repair is more likely when transverse arch hypoplasia is present. The aneurysm may be very large and thin walled, with rupture almost a certainty over a 15-year period. ^, These cases represent a major challenge and must be addressed directly. The option of “indirect management,” such as by an extra-anatomical bypass graft, is contraindicated because of the rupture risk. Standardized management techniques have not been established, but they include surgical, interventional, and hybrid techniques. ^, Optimal outcomes will be achieved with a multidisciplinary team including a cardiac surgeon, interventional cardiologist, and radiologist. The variables that influence treatment strategy include the severity of residual stenosis or hypoplasia, location of the aneurysm relative to the obstruction, suitability of “landing zones” for transcatheter devices, patient age and comorbidity, and likelihood of exclusion of the left subclavian artery or other brachiocephalic artery. Surgical management can vary but typically requires CPB, either via median sternotomy or left thoracotomy, with resection of the aneurysm and obstructive segment and interposition graft insertion. These procedures carry a mortality risk of 14% to 23%, and therefore endovascular management should be considered when anatomic details are favorable. ^, More recently, an open hybrid technique has demonstrated acceptable success.

Particularly in neonates and young infants, coarctation of the aorta can be well repaired from an anterior midline approach using CPB. Historically, use of hypothermic circulatory arrest was advocated, ^, but continuous CPB with antegrade cerebral perfusion can be used routinely for this approach ( Fig. 40.18 ).

Coarctation repair through median sternotomy using cardiopulmonary bypass (CPB). This approach is used when proximal aortic arch obstruction is severe or when an intracardiac procedure (usually a ventricular septal defect) is also repaired. (A) A standard median sternotomy incision is shown, and great vessels are dissected extensively, similar to that required for repair of interrupted aortic arch (see Section II ). (B) After standard preparation for CPB, cannulation is performed with the arterial cannula placed into brachiocephalic artery through a standard purse string, or preferably using a PTFE graft anastomosed to the right subclavian artery for arterial selective cerebral perfusion. Superior and inferior venae cava are cannulated individually. At institution of CPB, left and right branch pulmonary arteries are temporarily occluded. Dashed lines show incision in proximal aortic arch and transection sites at distal aspect of hypoplastic aortic isthmus, at descending aorta, and at ductus arteriosus. Cardioplegia needle is placed into mid-ascending aorta, and after clamping the ascending aorta cephalad to the needle, cardioplegic solution is administered (see text for details). After achieving adequate cardiac arrest, neck vessels are snared allowing continued cerebral perfusion into these arteries. The distal aorta is clamped and coarctation site resected along dashed lines shown in (A). Aortic isthmus and ductus arteriosus are both ligated, and temporary branch pulmonary artery ligatures are removed. An incision is made in undersurface of proximal aortic arch, and anastomosis is begun at midpoint of posterior aspect of the circumference of descending aorta as shown. A running monofilament absorbable suture is used. (C) Anastomosis is shown in its completed form, aortic clamps have been removed, and patient is separated from CPB (see “ Technique of Operation ” in Section 1 of Chapter 33 , and details in text of this chapter for approaches to closure of ventricular septal defect). BA , Brachiocephalic artery; IVC , inferior vena cava; LCA , left common carotid artery; LPA , left pulmonary artery; LSCA , left subclavian artery; PDA , patent ductus arteriosus; RPA , right pulmonary artery; SVC , superior vena cava; VSD , ventricular septal defect.

The midline approach is particularly useful when concomitant repair of intracardiac defects is contemplated; when coarctation is accompanied by severe hypoplasia of the proximal transverse arch; or when there is no proximal arch segment because the left carotid and brachiocephalic arteries share a common origin (“bovine” trunk) in association with hypoplasia of the segment between this common brachiocephalic trunk and the left subclavian artery. Defining how small of an aortic arch that precludes a thoracotomy approach has been debated, ^, but many series have demonstrated that the majority of cases can be performed via a thoracotomy with good results.

Technical and CPB considerations are similar to those involved with repair of interrupted aortic arch (IAA; see “ Interrupted Aortic Arch ” in Section II). The anterior midline approach has also been described for both children and adults with coarctation and other complex arch problems using interposition conduits. ^,

Generally, care of patients after coarctation repair is simple and similar to that according to any patient after thoracotomy. In neonates and young infants, usual care accorded to small babies who have been critically ill preoperatively is used (see Chapter 4 ).

Systemic arterial hypertension is usually present after operation, and its management is controversial. In older patients, mean arterial blood pressure is lowered to about 110 mmHg with nitroprusside for the first 24 hours, and the drug is then rapidly tapered and discontinued. Thereafter, if systolic blood pressure is greater than 150 mmHg, a β-adrenergic receptor blocking agent or angiotensin-converting enzyme inhibitor is administered for a few weeks. Care must be taken to avoid a dose that leads to hypotension.

In infants and young children, treatment is given less routinely for postoperative hypertension. Intravenous nitroprusside and nicardipine are effective first-line agents; however, esmolol is also effective.

Careful interrogation and observation of older patients postoperatively indicate that most have mild abdominal discomfort for a few postoperative days. In 5% to 10% of cases, this is prominent, and abdominal distention with hypoactive bowel sounds may develop.

Treatment consists of bowel decompression via a nasogastric tube and antihypertensive drugs. Antihypertensive therapy is begun and continued until symptoms subside. Intravenous fluids may be required for a day or two. In a study from 1972, Ho and Moss reported that routine treatment with antihypertensive drugs resulted in fewer (no) instances of laparotomy for abdominal pain than did nontreatment. In current practice, the need for laparotomy for abdominal crisis is rare.

The nature of chest tube drainage should be observed. Copious serous or milky drainage is probably chyle, a finding in about 5% of patients. The diagnosis can be confirmed with a fluid triglyceride level above 110 mg/dL (1.24 mmol/L), though clinical diagnosis usually suffices. The chest tube should be left in place until the patient has taken oral feedings. Initially, a low- or non-fat diet may be implemented with a strategy of nil per os and total parenteral nutrition reserved for more prolonged drainage. Additional surgical and/or lymphatic interventions may be considered in severe or prolonged cases of chylothorax (see “ Chylothorax ” under Special Considerations after Cardiac Surgery in Chapter 4 ).

Little specific information other than survival is available in this group of patients. The information suggests that similar VSDs have the same tendency to close as when coarctation is not present (see “ Spontaneous Closure ” under Natural History in Section I of Chapter 33 ). VSD in patients with coarctation, however, is more likely to be malaligned posteriorly, and malalignment VSDs are less likely to close than those without malalignment. In one study following 23 infants with coarctation and VSDs of various sizes in whom coarctation repair alone was initially performed before 3 months of age, 14 of 23 required subsequent VSD closure, and importantly, size of VSD was not correlated with need for closure. Other studies indicate that VSD size, as well as other characteristics of the VSD, are important predictors that surgical closure will be required (see “ Indications for Surgery ” for an in-depth discussion of surgical decision making for coarctation with VSD). Among neonates with large VSD undergoing only coarctation repair, by age 12 months, 12% of VSDs had become small, and by 24 months 19% had done so in the multi-institutional study of the CHSS. Results of repair of coarctation when VSD coexists, with regard to early, intermediate-term, and late upper body blood pressure, are presumably the same as when the coarctation is isolated, but this has not been confirmed by specific study.

In earlier eras, prior to 2000, early (hospital) mortality tended to be somewhat higher than in patients with isolated coarctation. ^, More recent studies, however, suggest that this may no longer be true. ^, A multi-institutional analysis from the Society of Thoracic Surgeons Congenital Cardiac Database reported a hospital mortality of 2/2474 (0.8%) for isolated coarctation repair versus 9/540 (1.7%) for coarctation (not hypoplastic aortic arch) and VSD repair ( P =.08). Earlier-era multi-institutional data suggested that the hazard for death may remain higher over time with VSD , but other studies indicate that presence of a VSD has no effect on either early or late risk, with excellent early and midterm outcomes reported. ^{, , ,} A higher proportion of patients with coarctation and VSD have two congenital anomalies affecting ventricular outflow, unlike those with isolated coarctation, and survival may be lower.

One-stage repair of the coarctation (by end-to-end anastomosis) and the VSD through a median sternotomy is currently the procedure of choice for most such situations. There are, however, alternative practices. Coarctation repair alone may be performed, ^, with later VSD closure if it remains large or the infant has failure to thrive. Also, coarctation repair with concomitant banding of the pulmonary trunk can be performed, with later removal of the band and VSD closure. Finally, a single-stage repair with two incisions has been described. The arch is repaired using a thoracotomy; the patient is then repositioned, and a median sternotomy is performed for VSD closure using standard CPB techniques.

A multi-institutional analysis including 51 institutions examined outcomes with various strategies for managing the VSD at the time of coarctation repair . Similar hospital survival was observed with primary complete and staged repairs of VSD and coarctation, but one-stage repair was associated with the lowest mortality in the most recent era ( Table 40.2 ). Although one-stage repair through a sternotomy is favored by most centers, one-stage repair of the coarctation via lateral thoracotomy followed by VSD repair via sternotomy has also been reported with good outcomes. Kanter and colleagues reported an analysis of 15 patients with 2 incisions and 11 with sternotomy only. There was no hospital mortality (0%, CL 0%–7%), and the two-incision group had significantly less need for circulatory arrest and shorter total CPB time, total cardiac ischemic time, and hospital length of stay. However, this approach represents a distinct minority (<10% of cases in a multi-center analysis).

Another approach involves coarctation repair with pulmonary trunk banding using absorbable material (polydioxanone). Band reabsorption occurred over approximately 6 months in an experience of 11 patients. VSD closure was necessary in only one following band reabsorption.

Authors of the 2013 STS Congenital Heart Surgery Database analysis concluded that primary coarctation or hypoplastic aortic arch repair can be performed with low mortality in neonates and infants. A single-institution study of 135 coarctation repairs in neonates with hypoplastic arch demonstrated that extended arch aortoplasty is an excellent choice of repair with low occurrence of recoarctation. However, those with concomitant cardiac defects are at higher risk for early postoperative morbidity and mortality ( Fig. 40.30 ).

Characteristics and early outcomes across a large multicenter cohort undergoing coarctation or hypoplastic aortic arch repair from the Society of Thoracic Surgeons congenital heart surgery database. (A) Mortality for coarctation or hypoplastic aortic arch (C/HAA)–isolated (group 1), C/HAA–VSD (group 2), and C/HAA–other major cardiac defects (group 3) compared with the overall cohort of 5025 patients. ( VSD , ventricular septal defect. * P =.001 compared with group 1. ** P <.0001 compared with group 2.) (B) Mortality for group 3 patients (C/HAA–other) stratified by whether they had C/HAA with LHAC (Shone syndrome; C/HAA + LHAC) defects versus C/HAA with other complex defects aside from LHAC (C/HAA + Complex Defects). ( C/HAA , Coarctation or hypoplastic aortic arch; LHAC , left heart aorta complex.)

(A from Ungerleider RM, Pasquali SK, Welke KF, et al. Contemporary patterns of surgery and outcomes for aortic coarctation: an analysis of the Society of Thoracic Surgeons Congenital Heart Surgery Database. J Thorac Cardiovasc Surg . 2013;145:150.)

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