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Adult Congenital Heart Disease With Prior Surgical Repair


An extensive variety of operations are used to correct or palliate congenital heart disease (CHD), often cloaked in the language of acronyms and eponyms. This chapter provides simple guidance for clinicians and sonographers in deciphering this occasionally confusing area. The approach to an adult postoperative patient should include some knowledge and history of what has been previously done for the patient. Attempting an echocardiogram without this knowledge can a time-consuming, frustrating experience and can lead to errors. Familiarity and experience with the echocardiographic appearance of postoperative CHD is an essential element to performing a good-quality study. ,

Historical Perspective And Timeline

Repair of congenital heart disease has evolved tremendously over the past 60 to 70 years, resulting in improved survival for many defects that would be ultimately lethal if left untreated. The recent advances in the care of patients with CHD have been driven by technology and innovative thinking. , Diagnostic techniques such as echocardiography, cardiac magnetic resonance imaging (CMRI), computed tomography (CT), and cardiac catheterization have also undergone significant advancements that have aided in this effort. The general trend in recent years has been to repair the CHD early and not perform the so-called palliative operations that were done in the past. As techniques have improved for managing small infants on cardiopulmonary bypass (CPB), this has now become possible. A listing of some of these operations and the timeline in which they were developed is shown in Table 144.1 . The early attempts to repair CHD were done without the use of CPB; a “closed heart” operation done on the beating heart. These operations were frequently palliative. Most of the early palliative operations were considered definitive at the time because no repair was yet available. The advent of CPB allowed the heart to be open and still for a more complex but complete repair. Beginning in the mid-1950s, this ushered in a rapidly expanding area of innovation in surgical technique. Experience in this technique continued and in the late 1970s expanded again with advances in bypass technology that allowed smaller infants to be placed on the bypass machine. With this advancement, the age at operation began to drop rapidly, and more operations could be performed in the first few months of life. Additionally, infants for whom there was previously no initial lifesaving palliation now could undergo successful repair as infants. Other more subtle technological advances, such as the use of cold-blood cardioplegic solutions to quiet the myocardium during bypass that was introduced in 1979, have helped to preserve myocardial function and improve outcome after surgery. As a result, patients repaired after 1980 are more likely to have better overall myocardial function, depending on the length and complexity of the operation.

TABLE 144.1
Significant Milestones in the Management of Congenital Heart Disease a
Year Physician(s) Procedure
1938 Gross Ligation of PDA
1944 Blalock, Taussig Systemic pulmonary shunt
1945 Gross, Crafoord, Nylin Repair of coarctation
1952 Muller Pulmonary artery band
1953 Gibbon Repair of ASD
1954 Lillehei Repair of VSD
1954 Glenn SVC-to-PA shunt
1955 Lillihei, Kirklin Repair of ToF
1959 Senning Atrial correction of TGA
1960 Waterston Aortopulmonary shunt
1963 Mustard Atrial correction of TGA
1964 Rastelli Conduit replacement of PA
1966 Rashkind Balloon atrial septostomy
1971 Fontan, Kreutzer Repair of tricuspid atresia
1973 Heymann, Rudolf PGE1 to open PDA
1976 Jatene Arterial switch of TGA
1983 Norwood Palliation of HLHS
1988 deLeval Total cavopulmonary anastomosis
1990 Marcelletti Extracardiac Fontan
1999 Sano RV-to-PA shunt
ASD, Atrial septal defect; HLHS, hypoplastic left heart syndrome; PA, pulmonary artery; PDA, patent ductus arteriosus; RV, right ventricular; SVC , superior vena cava; TGA, transposition of the great arteries; ToF, tetralogy of Fallot; VSD, ventricular septal defect.

a It is very helpful to know the timeline for various surgical repairs, particularly in patients in whom a detailed surgical history is not available. For example, a 40-year-old patient with d-transposition of great arteries is more likely to have had an atrial switch procedure (Mustard procedure) as opposed to an arterial switch operation (Jatene surgery). This table lists the timeline for various surgical procedures. Other landmark events in this field are use of prostaglandin (PGE1) (described in 1973, but clinical trials begun in 1978) and the use of two-dimensional echocardiography in the late 1970s.

Basic Concepts of Surgical Repair

The concepts used by some of these creative operations are very simply stated: (1) holes, abnormal communications—close them (patch, suture); (2) obstruction to normal flow—open up the narrowed area (resection, valvotomy, conduit); (3) too little pulmonary blood flow—add some (from the systemic circulation); (4) too much pulmonary blood flow—restrict it (close the hole, band the pulmonary arteries); and (5) only one pumping chamber—use it for the systemic circulation ( Box 144.1 ). Overall, the surgical repairs may be divided into three categories: palliative, anatomic, and nonanatomic.

BOX 144.1
Fontan or Single-Ventricle Concept

Holes Close them Patch or suture
Obstruction to flow Open it Resection, valvotomy, or conduit
Too little pulmonary flow Add flow from systemic circulation Central shunt, Blalock-Taussig shunt, Waterston shunt, Potts shunt
Too much pulmonary flow Restrict it Close the shunt or band the pulmonary arteries
Only one pumping chamber Use it for systemic circulation Fontan operation

Palliative Operations

Currently, these operations are typically performed as the initial, or sometimes only, step in patients with complex CHD. Palliative operations usually involve some control of pulmonary blood flow. It may be performed without bypass and can be accomplished in a short operative time and is therefore lower risk. Examples of these palliative operations are shown in Fig. 144.1 .

Figure 144.1, Palliative operations. 1, The classic Blalock-Taussig shunt is an anastomosis of the subclavian artery to the ipsilateral pulmonary artery (PA). 2, The modified Blalock-Taussig shunt uses a prosthetic tube interpositioned between the subclavian artery and PA. 3, A central shunt is a prosthetic tube that connects the ascending aorta (Ao) to the main (central) PA. 4, The Waterston shunt is a side-to-side anastomosis between the ascending Ao and right pulmonary artery (RPA). 5, The Potts shunt is a side-to-side anastomosis between the ascending Ao and left pulmonary artery (LPA). 6, A classic Glenn shunt is an anastomosis between the superior vena cava (SVC) and RPA. 7, Used to restrict pulmonary blood flow, a PA band is a constricting band placed around the MPA. LCCA , Left common cardiac artery; LSCA , left subclavian artery; RCCA , right common cardiac artery.

Control of pulmonary blood flow is an important consideration in the repair of CHD, particularly complex defects. Excessive pulmonary blood flow results in an infant who is well oxygenated (“pink”) but may be in heart failure from pulmonary edema. The surgical solution to this is to restrict the pulmonary blood flow by closing the offending shunt or by placing a palliative band around the main pulmonary artery (PA band), restricting blood flow to the lung. The band serves to protect the lung beds from excessive blood flow and increased pressure. Previously, pulmonary banding was routinely performed in young infants with shunt lesions because it did not require bypass. The child was allowed to grow to an age and size at which bypass could be safely performed. Because of the increasing ability to use bypass in infants, PA banding is no longer used in great numbers and is reserved mostly for complicated cases in which a complete repair cannot be safely performed. Smaller, premature babies are one group in whom PA banding is still used.

Insufficient pulmonary blood flow and an intracardiac right-to-left shunt will result in cyanosis (“blue baby”). If a complete repair is not immediately possible, surgical palliation may be performed to create an additional source of blood for the pulmonary arteries. This can be done with an aortopulmonary shunt. Types of aortopulmonary shunts include Blalock-Taussig shunt, Waterston shunt, and Pott shunt. The modified Blalock-Taussig shunt is the most commonly performed shunt currently. The Waterston and Pott shunts were abandoned because of complications, including excessive pulmonary blood flow and PA distortion. The classic Glenn shunt involved anastomosis of the superior vena cava (SVC) to the right pulmonary artery (RPA) and disconnection of the RPA from the main pulmonary artery (MPA). Although the classic Glenn shunt is now abandoned as a technique, this operation demonstrated that blood could flow into the lungs passively without a ventricular pump and was an important precursor to the concept of single ventricle repair, described later in this chapter. The classic Glenn shunt was later modified as a bidirectional Glenn shunt in which the SVC is anastomosed to the RPA but the RPA remains connected to MPA as the second stage for Fontan operation.

Anatomic Operations

The goal of an anatomic correction is to repair the CHD such that the patient has a four-chamber heart and two pumping ventricles. The repair might be simple, such as septal defect closure, or complex, when a combination of defects is present. It may be approached in one stage or in more than one stage. These operations are usually final. Most are now accomplished in the first year of life. Usually, CPB is needed.

If there are simple shunt defects (“holes”), they are most frequently repaired either by direct suture closure or by a patch. The patch material could be autologous pericardium or prosthetic material such as Dacron. Primary repair is preferable, but some factors (i.e., unusual location of defect, prematurity) preclude early primary repair and require initial palliation. Shunts may be thought of as “high pressure” (e.g., when a high-pressure chamber or vessel [left ventricle or aorta] is connected to a chamber or vessel that is normally under low pressure [right ventricle or PA]). Examples of high-pressure shunts are ventricular septal defects (VSDs) and patent ductus arteriosus (PDA). When pressure and flow are transmitted through the shunt from a high-pressure to a low-pressure area, the need for early surgery or palliation is greater, and operation should take place early to protect the pulmonary vasculature. By contrast, a “low-pressure” shunt (e.g., when a low-pressure area is connected to another low-pressure area, such as an atrial septal defect) rarely requires early surgery, and repair can usually wait until the patient is older and bigger.

If the cardiac defect is an obstruction and involves a cardiac valve, repair might involve either opening up the valve leaflets (valvotomy) or resecting the valve or obstructive muscle. The timing of these operations or interventional catheterization procedures often depends on the degree of obstruction. Therefore, the echocardiographic valvular gradient becomes an important factor in determining the need and timing of repair. The narrow or obstructed area might also be repaired with a patch or by interposition of a conduit or prosthetic valve. Conduits and artificial valves have an obvious disadvantage because of their inability to grow with the patient. Therefore, valves and conduits placed early in life will ultimately require replacement. There may be then the need for multiple operations because of the rapid growth seen in the pediatric age group.

Nonanatomic Operations

Nonanatomic repair most often includes a staged approach to a single usable ventricle, referred to as a “Fontan” operation. In these instances, the one available ventricular pump is used for the systemic circulation. The pulmonary ventricle is bypassed, and the entire venous return from the SVC and inferior vena cava (IVC) goes directly into the pulmonary arteries, separating the systemic and pulmonary circulation. The net result is a patient with relatively normal oxygen saturations but no pulmonary pump. A completed Fontan operation is currently accomplished in three stages. If a patient has had three operations within the first few years of life, it is highly likely that he or she had some variation of single-ventricle repair. Older adults who had an operation before 1985 may have had this done in two stages, with the later stage at an older age.

The first stage of the Fontan operation is done to gain control of the pulmonary circulation. The kind of operation varies depending on the cardiac anatomy and status of the pulmonary blood flow. This could involve placement of a band around the MPA to restrict pulmonary blood flow or placement of an aortopulmonary shunt to increase pulmonary blood flow. If the systemic outflow tract is inadequate, pulmonary outflow is used to reconstruct the systemic outflow tract (Norwood procedure). Hence, a source of pulmonary blood flow in the form of a shunt is needed. It may be a Blalock-Taussig shunt or a right ventricle to PA shunt (Sano modification), which is favored by some centers. In either case, mixed arterial and venous blood is delivered to the aorta and the body. In patients with CHD in whom the pulmonary blood flow and pressure are in an acceptable range and there is no systemic outflow tract obstruction, the first-stage operation can sometimes be skipped.

The second stage of the Fontan operation involves connection of the SVC to the PA. This is referred to as “hemi-Fontan” or “bidirectional Glenn shunt” and is typically performed around 6 months of age. The lower body venous return via IVC still enters the systemic circulation, resulting in continued desaturation after this stage. The third and final stage of the Fontan operation is often referred to as “completion of Fontan,” in which the venous return from the IVC is now directed into the pulmonary arteries, completing the separation of the systemic and pulmonary circulations. This final stage is performed between 18 months to 3 years of age, depending on the modification of the Fontan connection performed and the systemic venous anatomy. There is some variation between different institutions in terms of the timing for this final operation. The Fontan circuit may be fenestrated in certain cases to allow a small right-to-left shunt at the atrial level.

Important Echocardiographic Considerations In The Postoperative Patient

Some of the unique concepts pertaining to surgical repair of CHD that may influence the performance and interpretation of the echocardiographic study follow:

  • The pulmonary valve is expendable, and pulmonary insufficiency is very well tolerated for many years before some form of intervention is required.

  • The primary goal of surgical repair in many cases of CHD is to control the pulmonary blood flow. Therefore, a detailed examination of pulmonary arteries, pulmonary blood flow, and pulmonary pressures is important. Determination of pulmonary pressure can be done using tricuspid regurgitant flow velocities or using the VSD shunt gradient if present.

  • Patches placed in the heart become endothelialized over time and become part of the heart. A relatively large patch placed in an infant heart will be a very small part of the adult heart and may be invisible on the echocardiogram. During the echocardiographic study, thorough evaluation for any residual shunts should be performed. This finding has clinical implications for endocarditis prophylaxis.

  • Detailed examination of all available chambers and valves during an echocardiographic study is crucial in the management of a patient with CHD.

  • Patients with CHD may often have “missing parts.” Do not assume that the inability to image a chamber or valve is caused by inadequate technique or echocardiographic window. The chamber or valve might not be present as a part of the CHD. For example, the pulmonary valve may be “missing” in postoperative patients with tetralogy of Fallot (ToF) that was repaired with a transannular patch.

  • The route taken by the blood flow in and out of the heart may vary in patients with CHD. It is important to trace the blood flow from the point of entry into the heart to the exit point out of the heart by following the segmental analysis, as described in Chapter 140 .

  • Many postoperative adult patients with CHD have poor acoustic windows, and transthoracic echocardiography may be suboptimal. Transesophageal echocardiogram may play an important role (refer to Chapter 140 ), and CMRI is rapidly gaining utility for this cohort of patients. , CT is a good option when CMRI is contraindicated in certain cases.

Representative Case Examples

A few case scenarios are discussed here to help develop an understanding of commonly encountered postoperative patients with CHD. Exhaustive examples of every congenital heart operation are beyond the scope of this chapter.

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