Congenital heart procedures in adults are frequently reoperations, however, protocols for reoperations in acquired heart surgery do not mesh completely with the challenges presented by ACHD patients. Risk factors for traumatic repeat sternotomy in ACHD patients differ from those identified in patients with acquired heart disease, which often focus on patent coronary bypass grafts.7 Femoral cannulation is often complicated in congenital heart patients who have undergone multiple interventional catheterizations during their growth years, resulting in stenotic or occluded femoral vessels. We use a selective cannulation strategy and only routinely cannulate patients with significant risk factors. Other risk factors for sternal reentry injury in ACHD include retrosternal conduits, particularly oversized and calcified homografts. We specifically look for evidence of conduit fusion to the sternum, which should be suspected when the conduit does not move with the cardiac cycle on lateral angiograms. Patients with pulmonary hypertension, right ventricular enlargement, prior sternal infections, aneurysms of the right or left ventricular outflow tracts, and pectus excavatum deformity are at increased risk, and qualify for preliminary vascular access dissection and pursestring placement. Patients with multiple risk factors may be placed on bypass to decompress the right ventricle prior to commencing sternal division.
We excise previous sternotomy scars and remove sternal wires. The xiphoid process is removed, and cautery dissection is begun at the inferior sternal edge. The oscillating saw is used to divide the anterior sternal table. Rakes are used to elevate the two sides of the sternum and expose the retrosternal scar. Short segments of retrosternal scar are released, followed by oscillating saw division of the sternal bone, and this proceeds superiorly until the entire sternum is divided.
In the event of cardiac or great vessel penetration during sternotomy, when we have not electively exposed vessels for cannulation, we release the sternal retractors, and immediately extend the neck dissection up and to the right to expose the innominate artery and the internal jugular or high innominate vein. These vessels are cannulated through pursestrings, and bypass is initiated.
Reoperative Sternotomy Technique with Emergency Bypass Via Neck and Inferior Vena Cava Dissection
In patients in whom venous access cannot be achieved in the suprasternal area, we dissect the inferior vena cava just above the diaphragm. This approach has been described as simplified aortic cannulation.8 The sternotomy is then completed with the patient in Trendelenburg. We continuously infuse carbon dioxide into the operative field during every operation to reduce the risk of air embolism, although the evidence that this reduces stroke rates is not conclusive.9
To reduce adhesion formation, and decrease the risk of future sternotomy, we prevent cardiac desiccation by covering the heart with saline-soaked gauze. At the completion of ACHD repairs, we place antiadhesion materials to decrease retrosternal adhesions. Expanded polytetrafluoroethylene (PTFE) is commonly used in some centers;10 however, capsule formation often obscures natural tissue planes, making subsequent reoperative dissection more difficult. Bioresorbable film prototypes made of polyethylene glycol and polylactic acid have been developed and tested for cardiac operations. These bioresorbable films significantly reduce adhesion formation, and their rapid resorption appears to mitigate capsule formation.11 Sheets of extracellular matrix derived from pig jejunum is now approved for use as a pericardial substitute.12
Reducing Incisional Trauma
Multiple incisional approaches have been described to improve the cosmetic result after open heart surgery. These include partial upper and lower sternotomy, transxiphoid, anterior thoracotomy, and submammary incisions. Despite its visibility, median sternotomy may be the least traumatic incision for ACHD patients, allowing the surgeon to avoid vascular trauma from peripheral cannulation, avoid intercostals muscle, vessel and nerve trauma, and thereby eliminate post-thoracotomy pain syndrome. Median sternotomy allows direct aortic control for safe, effective cannulation, decannulation, de-airing, and cardioplegia administration with minimal risk of dissection. Median sternotomy also ensures direct and rapid access to the entire mediastinum, allowing surgeons to deal with unanticipated anatomical variations discovered at surgery, which are not uncommonly found in ACHD patients.
The advent of transcatheter device closure for atrial septal defects has significantly changed the average complexity level of ACHD case loads. Patent foramen ovale and most secundum defects are effectively closed with devices, and are rarely referred for surgical closure in programs with effective interventional catheterization teams. Sinus venosus and primum defects, transitional and complete atrioventricular canal, common atrium, and secundum defects with deficient inferior rims are referred for surgery, and we repair these on cardiopulmonary bypass with cardioplegic arrest.
Our venous cannulation strategy for atrial septal defects is bicaval, via the right atrial appendage up the superior vena cava, and down the inferior vena caval junction into the inferior vena cava. Smaller defects, which in the past could be closed primarily, are now rarely referred for surgical closure, and we find that repairs are best performed with patch materials, to create tension-free suture lines and avoid repair breakdowns and recurrences.
For sinus venosus defects, we place a right-angled cannula in the innominate vein, to enable exposure of partial anomalous pulmonary veins entering the superior vena cava.
The approach is through a lateral incision to avoid the sinus node area, and is extended superiorly just far enough to expose the upper pulmonary vein entrance point (Fig. 60-2A). A "no-touch" technique is maintained in the sinus node area. A pericardial patch is used to close the atrial incision to avoid superior vena caval stenosis (Fig. 60-2B).
(A) A Sinus venous defect with partial anomalous pulmonary venous return. (B) The pulmonary veins are baffled to the left atrium with native pericardium. (C) The superior vena cava to right atrial junction is patched with pericardium to prevent SVC obstruction. RUPV = right upper pulmonary vein; SN = sinus node area; SVASD = sinus venosus atrial septal defect; SVC = superior vena cava.
In patients with primum atrial septal defects, the cleft mitral valve is routinely repaired with running polypropylene suture lines approximating the line of contact between the leaflet segments. Even patients with competent valves are repaired, as late onset of cleft regurgitation is known to occur. Patients at risk for mitral stenosis, particularly those with a single papillary muscle in the left ventricle, may have their clefts left open to avoid valvar stenosis. Results for these repairs are excellent, even in patients at advanced ages.13
Surgery for Ebstein's anomaly can be performed in older patients at low risk and with good late outcome. The operation is comprised of tricuspid valve repair or replacement and concomitant procedures such as atrial septal defect closure, arrhythmia surgery (the maze procedure), and coronary artery bypass grafting.14 Repair techniques for these patients continue to evolve. We believe the presence of an untethered and well-developed anterior tricuspid valve leaflet increases the chance of a successful repair, and have used the Cone technique in adult patients.15 This repair requires dissection of the anterior and posterior tricuspid valve leaflets from their right ventricular attachments. The free edge of the leaflet is then rotated clockwise and sutured to the septal border of the anterior leaflet. This produces a cone-shaped valve, fixed distally at the right ventricular apex, and proximally at the tricuspid valve annulus. The septal leaflet is incorporated into the cone wall whenever possible, and the atrial septal defect is closed. Results have been good with low mortality, significantly less tricuspid regurgitation, and improvement in functional class.
In the modern era, the primary cause of death for adult patients with cyanotic lesions is arrhythmia followed by heart failure.16 Fontan patients may present with arrhythmia and complications related to systemic ventricular failure, protein-losing enteropathy (PLE), systemic venous pathway obstruction, and semilunar and atrioventricular valve dysfunction. Initial evaluations must focus on ensuring a completely unobstructed vascular pathway to the lungs. The different types of surgical techniques historically used to create the Fontan circulation each have characteristic complications. Patients with intracardiac baffles and atriopulmonary connections may present with extreme right atrial enlargement, resulting in stagnant flow, right pulmonary vein compression, and arrhythmia.
Fontan conversion involves takedown of the previously created venous connection, and creation of an extracardiac cavopulmonary connection with a conduit. Because the extracardiac Fontan excludes the systemic veins from the heart, any catheterization procedures requiring atrial level intervention, particularly electrophysiology interventions, must be planned before conversion. Therefore, we plan Fontan conversions with our electrophysiology team, and frequently combine Fontan conversions with arrhythmia surgery,17 and treatment of atrioventricular valve dysfunction. Valve repairs are often complex in these patients, and replacements are often required to achieve good hemodynamic results.18 Results depend on the patients' underlying anatomy, right ventricular function, and pulmonary vascular resistance.
We perform extracardiac Fontan procedures with bicaval cannulation, and leave the heart warm and beating whenever possible. The inferior vena cava is transected at the cavo-atrial junction under a clamp and the cardiac end is oversewn with 4-0 polypropylene running suture. We use ring reinforced expanded PTFE grafts from 19 to 23 mm in diameter, and leave enough length to avoid right pulmonary vein compression. The superior anastomosis to the superior vena caval junction with the right pulmonary artery is then constructed with running 6-0 polypropylene suture. Hybrid stenting procedures, in which the interventional cath team comes into the cardiac operating room to deploy stents, are used to treat stenoses in the retroaortic pulmonary arteries if they are stenotic.
In patients with complex cardiac anatomy, these Fontan revision procedures may best be performed with the participation of electrophysiology. This ensures effective interruption or ablation of reentrant pathways, which may not follow the patterns seen in patients with acquired heart disease and normal cardiac anatomic relationships. A variety of Maze type procedures have been described in an effort to disrupt atrial reentrant pathways. The unpredictable anatomy of the conduction tissue in ACHD patients has resulted in frequent need for pacemaker insertion. In many centers, customized pacemaker therapy has been advocated for management of patients after Fontan conversion. However, based on an experience with 120 Fontan conversions from 1994 to 2008, which began with a flexible approach to each patient's anticipated pacing needs, Tsao and coworkers now recommend routine placement of a dual-chamber antitachycardia pacemaker with bipolar steroid-eluting epicardial leads in patients undergoing Fontan revision.19
Right Ventricular Outflow Tract Reconstruction
Right ventricular outflow tract reconstruction after previous repair of tetralogy of Fallot, double outlet right ventricle, pulmonary atresia, truncus arteriosus, and arterial switch procedures are increasingly common, as patients who underwent successful neonatal and infant repairs are returning with pulmonary insufficiency and/or stenosis, resulting in right ventricular dysfunction, exercise intolerance, arrhythmias, and sudden death.20 The first percutaneous pulmonary valve replacement was performed by Bonhoeffer in 2000,21 and this therapy is increasingly available as clinical trials have shown safety and efficacy.22 This less invasive therapy has accelerated the study of ACHD patients with pulmonary insufficiency, who have often been followed for years to avoid the trauma of reoperation. The growing experience with transcatheter pulmonary valve insertion into previously placed RVOT homografts suggests that homograft rupture is a rare known complication, occurring in 3.9% in an early series of implants, with stent fractures being a more common (20%) and benign complication.23 With surgical standby patients with rupture can be placed on emergent bypass, and undergo surgical repair with good results.24 Indications for pulmonary valve replacement in ACHD patients are evolving, and optimal indications and timing remain elusive. Preoperative evaluation with echocardiography, magnetic resonance imaging (MRI), and cardiac catheterization are used to identify concomitant lesions, particular patent foramen ovale, coronary anatomy, and right ventricular dimensions and function.
For patients not amenable to transcatheter pulmonary valve implantation, our standard surgical approach includes median sternotomy, bicaval cannulation, and repair on cardiopulmonary bypass with moderate hypothermia. These repairs may be performed without cardioplegic arrest if provocative preoperative testing (bubble test with Valsalva)25 shows no right to left shunting at the atrial or ventricular levels. Patients with positive bubble studies have aortic cross-clamping and cold blood cardioplegic arrest. We control the branch pulmonary arteries with tourniquets and place a right ventricular vent in the atrium to create a clear operative field. If a previous right ventricular incision or patch is present, this is used as a safe reentry point, and the incision is extended far enough to inspect the right ventricle and allow resection of obstructing intracavitary muscle bundles. Pulmonary valve replacement options include pulmonary homograft, aortic homograft, bovine jugular vein graft, bioprosthetic valve, and mechanical prosthetic valve.
Homografts are selected based on availability and echocardiographic estimates of normal pulmonary valve annulus size for the given patient weight. Leaving the graft too long will produce a kink when the graft is pressurized, with resultant obstruction. We perform the distal pulmonary artery anastomosis with a running 5-0 or 6-0 monofilament polypropylene suture, and then trim the proximal homograft muscle cuff to match the incision in the right ventricle. The proximal anastomosis is constructed with a larger running suture and needle, and care is taken to avoid the left main and anterior descending coronary arteries (Fig. 60-3). Left anterior descending coronary arteries and dual anterior descending vessels are specifically ruled out on preoperative studies, and when present, are left undisturbed by carefully positioning the right ventricular incision. The anterior portion of the outflow tract is completed with a patch of native or bovine pericardium, PTFE, or extracellular matrix patch.
Right ventricular (RV) outflow tract reconstruction with a pulmonary homograft. The posterior suture line has been completed with a running suture, and the length of the anterior wall is measured to see if a patch augmentation should be used to prevent distortion of the homograft pulmonary valve (HPV) annulus.
The Bovine jugular vein valve is sized and implanted in a similar way to homografts, with a distal running suture line. The proximal graft is beveled, so that a separate hood patch is not necessary (Fig. 60-4). Midterm results for bovine jugular vein grafts in adult patients are good, but long-term durability is unproved.26
Right ventricular (RV) outflow tract reconstruction with a bovine jugular vein graft (BJVG). The posterior graft length must be short enough to prevent kinking. These grafts can be trimmed to cover larger defects in the anterior right ventricular free wall, so that additional patches are rarely needed.
Bioprosthetic and mechanical valves are positioned in the right ventricular outflow tract at the normal pulmonary valve annulus in patients with normal right ventricular anatomy, or in a position that avoids sternal compression. (More distal implantation is often necessary after repair of truncus arteriosus and pulmonary atresia.) We have used both an interrupted pledgeted horizontal mattress suture technique, and a running polypropylene suture technique for these implants (Fig. 60-5). Both techniques require that the valve suture line be constructed so that the valve orients correctly toward the main pulmonary artery bifurcation, fighting the tendency for the valve to aim up at the sternum. A patch is used to close the distal main pulmonary artery up to the level of the valve, valve sutures are passed through the patch, and the patch is then completed over the proximal right ventricular outflow tract incision.
Right ventricular (RV) outflow tract reconstruction with a bioprosthetic valve (BV). A running suture technique was used on the posterior wall and a Dacron patch was used to augment the anterior wall of the right ventricular outflow tract.
Advantages and disadvantages exist for each pulmonary valve replacement option.27 Homografts and bovine jugular veins have length and can be used to span long gaps between the right ventricle and the branch pulmonary arteries. The distal anastomosis can be configured to repair stenotic sections of the main pulmonary artery and the proximal branches. They also form suitable conduits for subsequent insertion of transcatheter pulmonary valves in the future if they become stenotic or insufficient. We try to tailor our conduit decisions to meet the implantation requirements for transcatheter pulmonary valve insertion. These evolving requirements are factored into our decision process in selecting a conduit during our current surgical pulmonary valve replacements. Currently available bioprosthetic valves are also suitable for subsequent insertion of a transcatheter valve, as the valve ring provides a stable landing zone for the transcatheter valve stent. Mechanical valves do not allow subsequent placement of a transcatheter pulmonary valve, and we have reduced our use of these in the pulmonary position. Right ventricular outflow tract reconstruction continuity between the right ventricle and the pulmonary arteries can now safely be performed with low morbidity and mortality, and conduit options continue to expand.28
Left Ventricular Outflow Tract Reconstruction
Isolated areas of left ventricular outflow tract obstruction are less common in ACHD patients than in those with acquired left-sided lesions. ACHD patients with left ventricular outflow tract obstruction should be evaluated for upstream and downstream stenoses, as multiple levels of obstruction are common. Patients with Shone's syndrome often undergo numerous surgical and interventional palliations over their lifetimes, and these patients are symbolic of the nature of complex left ventricular outflow tract disease, whereas our interventions should usually be classified as palliative. Adult congenital teams should be prepared to perform primary Ross, Ross-Konno, and Konno procedures, and deal with reoperations for each of these palliations.
The Ross operation is often used in pediatric patients with complex left ventricular outflow tract obstruction to treat combined valvar and supravalvar lesions, avoid anticoagulation, and maintain some growth potential. These patients may require reoperations as adults to replace failing neo aortic valves, and stenotic or regurgitant pulmonary valves. Follow-up of right ventricular reconstructions after Ross operations suggests that 4% of patients will require conduit replacement for right ventricular (RV) dysfunction at 10 years. Conduit size less than 14 mm is an independent predictor of allograft dysfunction.29 Freedom from reoperation for regurgitation of the pulmonary autograft in the aortic position are quite variable, with reports from 87%30 to 96%.31 The advent of percutaneous aortic and pulmonary valve options may increase the use of the Ross operation, because reintervention on the autograft and allograft may not require reoperation. Aneurysmal dilation of the neo aortic root after the Ross operation is related to use of the root technique, and may be seen in up to 11% of patients at 7 years after surgery. Good outcomes after reoperation can be achieved, but successful repair of the autograft is more likely if the diagnosis is made early, before the neo-aortic valve becomes insufficient.32
The Konno aortic ventriculoplasty is used to treat complex left ventricular outflow tract obstruction in patients with supravalvar, valvar, and subvalvar obstruction, and may be encountered in adults who require initial treatment, or reoperations for valve malfunction or outgrown valves. The Ross-Konno, using the transplanted pulmonary autograft with a graft or infundibular extension, has been shown to increase in size as patients grow, making this an excellent option in pediatric patients. In a review of 53 patients operated from 1980 to 2004, with an average age of 19, Suri and coworkers reported risk factors for overall mortality included New York Heart Association class (hazard ratio 2.22, p = .04) and longer bypass time (hazard ratio 1.93/hour, p = .04). The cumulative probability of aortic valve reoperation was 19% at 5 years and 39% at 10 years, occurring in 15 patients at a median of 3.8 years. Pulmonary regurgitation was detected in six patients. Pulmonary valve replacement was performed in three (6%).33
Reoperations after Ross, Ross-Konno, and Konno procedures may be particularly challenging. This is especially true if the right ventricular outflow tract has been reconstructed with a large patch covering the anterior wall of the ascending aorta. Exposure of the aortic root then necessitates reentry into the right ventricle, which is best managed with bicaval cannulation, allowing isolation of the right ventricle and a blood-free operative field. Given the high incidence of reoperations on these patients, antiadhesion barriers are worthy of consideration at the time of closure.
Maintaining a functional conduction system is a crucial aspect of reducing the cumulative lifetime trauma for a patient with congenital heart disease. Despite best efforts to prevent injury to the conduction tissues, ACHD patients are at risk for a wide array of conduction delays, as well as atrial and ventricular tachyarrhythmias. Pacemaker and defibrillator insertion, lead extractions, and generator changes are frequently complicated in ACHD patients by unusual anatomic pathways and stenotic veins. Epicardial lead placements are often necessary in single ventricle patients who have limited or no venous access to the endocardium. Common indications for lead removal include pocket infection, malfunctioning leads, skin erosion, endocarditis/septicemia, vena cava thrombosis, and painful leads. Lead extraction technology is evolving, and can be safely managed as a hybrid effort with a surgeon and electrophysiologist working together. A number of lead removal catheters are available using blades or laser energy to excise embedded leads. Surgical support is necessary in the event of cardiac perforation. Outcomes are generally good, with sepsis being the strongest predictor of death after pacemaker device removal.34
Supraventricular and ventricular arrhythmias are a major cause of morbidity and mortality in adult patients with congenital heart disease. For patients with atrial fibrillation or flutter undergoing open heart repairs, a right-sided Maze procedure can be performed, with the expectation of 93% freedom from arrhythmia and improvement in functional class.35
Minimally invasive approaches to arrhythmia surgery, such as the mini-Maze procedure, are increasingly popular in patients with acquired heart disease and arrhythmia.36 These approaches may be difficult to accomplish in certain ACHD patients because of unusual anatomical relationships, and extensive reoperative scarring, which may limit exposure through small incisions. The Cox-Maze procedure for supraventricular arrhythmias in ACHD patients is often complex, and an alternative approach using intraoperative monopolar irrigated radiofrequency ablation (IRA) has been described with good results for patients undergoing elective cardiac surgery.37
Unified Approach for Hybrid Procedures
We define hybrid procedures as those using combined surgical and interventional personnel and technology during a single operation. Hybrid procedures can be performed in the catheterization laboratory, the operating room (with C-arm angiography), or ideally in a hybrid procedure suite. We select the venue based on which technology (interventional or surgical) is most important for a given procedure. The advent of percutaneous cardiac valve replacement and endovascular stenting highlights the need to embrace this unified team approach for adult congenital heart patients. In patients requiring interventional, surgical, and electrophysiologic procedures, we attempt to integrate the procedures into a single hybrid operation, with the surgical team providing the least traumatic form of vascular access. Surgeons can also provide central vascular and direct cardiac access for sheath placement in patients with stenotic or occluded peripheral vessels. We routinely place aortic and pulmonary artery stents in the operating room using direct vision, video assisted cardioscopy, and angiography (Fig. 60-6). Elective or emergent cardiopulmonary bypass support should be available on demand in the hybrid operating room or catheterization laboratory (Fig. 60-7).
Operative image of a hybrid procedure, with surgical exposure of the right ventricle through a subxiphoid incision (SI), and placement of a transcardiac sheath (TS), followed by interventional catheterization.
A cardiopulmonary bypass circuit (CBC) on standby in the hybrid catheterization laboratory, enabling rapid setup and support with transport capability.
Real-time consultation between surgeons and interventionists may enhance outcomes for vascular stent implants, because stent placements can be planned to minimize subsequent operative trauma. With a surgeon's input at the time of implantation, pulmonary artery stents may be positioned more proximally to avoid tearing into the branch pulmonary arteries at reoperation when the stent is outgrown. Similarly, aortic arch stents can be positioned more proximally to minimize the distance down the arch the surgeon must dissect if reoperation is required to open a stent that cannot reach adult size.
Primary and recurrent coarctation of the aorta in adult patients is increasingly managed percutaneously with balloon dilation and stents.38 We provide surgical backup for these procedures in the event of device migration, dissection, and rupture, and occasionally to establish vascular access. When transcatheter therapy is not feasible, we proceed with surgical repair of adults with coarctation and aortic arch obstruction. These operations are performed through a left thoracotomy in patients with a left aortic arch, and the perfusion team is on standby for left atrial appendage to descending aortic cardiopulmonary bypass. Three general techniques can be used, including coarctation resection with end-to-end anastomosis, onlay patch enlargement with tissue or prosthetic patch, and synthetic tube interposition. Aortic mobility is limited in adult patients, and tension-free repairs may require interposition grafts. Postoperative hypertension is common and responds to sodium nitroprusside. We use subcutaneous local anesthetic infusion catheters to control postoperative pain, and anticipate labile blood pressure responses in patients with longstanding hypertension. Mortality is rare, and at follow-up, 75% of patients will be normotensive without medication.39