Bidirectional Glenn shunt in association with congenital heart repairs: the 1(1/2) ventricular repair

Congenitally Corrected Transposition of the Great Arteries: Mid-term Outcomes of Different Surgical Strategies

BACKGROUND

Optimal management for congenitally corrected transposition of the great arteries (ccTGA) is controversial. We applied different surgical strategies based on individual variations in our single-centered practice over 10 years, aming to describe the mid-term results.

METHODS

From January 2008 to June 2021, 90 patients with ccTGA were reviewed and grouped by three different surgical strategies: 41 cases with biventricular correction as biventricular group, 11 cases with 1.5 ventricular correction as 1.5 ventricular group, and 38 cases with Fontan palliation as univentricular group. The mean age at primary surgery was 41.4 ± 22.7 months. Patients were followed for mortality, complications, reoperation, cardiac function, and valve status.

RESULTS

The median follow-up period was 5.1 years (range, 1.5-12.5 years). The overall 10-year survival and freedom from reoperation rate was 86.7 and 82.4%, respectively. There were 3 early deaths and 3 mid-term deaths in the biventricular group, while 2 early deaths and 1 mid-term deaths were reported in the univentricular group. Although 1.5 ventricular group presented no death and the fewest complications, we still found similar mortality (p = 0.340) and morbidity (p = 0.670) among the three groups. The bypass time, aortic-clamp time, and ICU stay length were the longest in the biventricular group, followed by the 1.5 ventricular group (p < 0.001). However, in mid-term follow-up, biventricular and 1.5 ventricular groups both showed excellent cardiac function and obvious improvement of tricuspid regurgitation (p = 0.008 and p = 0.051, respectively). Fontan palliation provided acceptable mid-term outcomes as well, despite a lower ejection fraction.

CONCLUSION

Satisfactory mid-term outcomes could be achieved for highly selected ccTGA patients using the whole spectrum of surgical techniques. Moreover, 1.5 ventricular correction, as a new emerging technique in recent years, might hold great promise in future practice.

Bidirectional Glenn for residual outflow obstruction in Tetralogy of Fallot

BACKGROUND

Residual right ventricular outflow obstruction during Tetralogy of Fallot repair necessitates peri-operative revision often requiring trans-annular patch with its negative sequels. Bidirectional Glenn shunt in this setting reduces trans-pulmonary gradient to avoid revision.

METHODS

Bidirectional Glenn shunt was added during Tetralogy repair in patients with significant residual obstruction. A total of 53 patients between January, 2011 and June, 2018 were included. Final follow-up was conducted in July, 2018.

RESULTS

Mean age at operation was 5.63±3.1 years. Right to left ventricular pressure ratio reduced significantly (0.91±0.09 versus 0.68±0.05; p&lt;0.001) after bidirectional Glenn, avoiding revision in all cases. Glenn pressures at ICU admission decreased significantly by the time of ICU discharge (16.7±3.02 versus 13.5±2.19; p&lt;0.001). Pleural drainage ≥ 7 days was seen in 14 (26.4%) patients. No side effects related to bidirectional Glenn-like facial swelling or veno-venous collaterals were noted. Mortality was 3.7%. Discharge echocardiography showed a mean trans-pulmonary gradient of 32.11±5.62 mmHg that decreased significantly to 25.64±5 (p&lt;0.001) at the time of follow-up. Pulmonary insufficiency was none to mild in 45 (88.2%) and moderate in 6 (11.8%). Mean follow-up was 36.12±25.15 months (range 0.5-90). There was no interim intervention or death. At follow-up, all the patients were in NYHA functional class 1 with no increase in severity of pulmonary insufficiency.

CONCLUSION

Supplementary bidirectional Glenn shunt significantly reduced residual right ventricular outflow obstruction during Tetralogy of Fallot repair avoiding revision with satisfactory early and mid-term results.

Echocardiographic parameters associated with biventricular circulation and right ventricular growth following right ventricular decompression in patients with pulmonary atresia and intact ventricular septum: Results from a multicenter study

BACKGROUND

In patients with pulmonary atresia, intact ventricular septum (PA/IVS) following right ventricular (RV) decompression, RV size and morphology drive clinical outcome. Our objectives were to (1) identify baseline and postdecompression echocardiographic parameters associated with 2V circulation, (2) identify echocardiographic parameters associated with RV growth and (3) describe changes in measures of RV size and changes in RV loading conditions.

METHODS

We performed a retrospective analysis of patients who underwent RV decompression for PA/IVS at four centers. We analyzed echocardiograms at baseline, postdecompression, and at follow up (closest to 1-year or prior to Glenn circulation).

RESULTS

Eighty-one patients were included. At last follow-up, 70 (86%) patients had 2V circulations, 7 (9%) had 1.5 ventricle circulations, and 4 (5%) had single ventricle circulations. Follow-up echocardiograms were available in 43 (53%) patients. The majority of patients had improved RV systolic function, less tricuspid regurgitation (TR), and more left-to-right atrial shunting at a median of 350 days after decompression. Multivariable analysis demonstrated that larger baseline tricuspid valve (TV) z-score (P = .017), ≥ moderate baseline TR (P = .045) and smaller baseline RV area (P < .001) were associated with larger increases in RV area. Baseline RV area ≥6 cm² /m² had 93% sensitivity and 80% specificity for identifying patients who ultimately achieved 2V circulation. All patients with RV area ≥8 cm² /m² at follow up achieved 2V circulation. This finding was confirmed in a validation cohort from a separate center (N = 25). Factors associated with achieving RV area ≥8 cm² /m² included larger TV z-score (P = .004), ≥ moderate baseline TR (P = .031), and ≥ moderate postdecompression pulmonary regurgitation (P = .002).

CONCLUSIONS

Patients with PA/IVS and smaller TV annuli are at risk for poor RV growth. Volume-loading conditions signal increased capacity for growth sufficient for 2V circulation.

One and half ventricle repair: rationale, indications, and results

Surgical strategies in patients with functionally or anatomically borderline right ventricles include a high-risk biventricular repair, a Fontan procedure, or a one and half ventricle repair (also referred to as the partial biventricular repair). One and half ventricle repair (1.5VR) circumvents the high early mortality of a biventricular repair and also the late morbidity of the Fontan. The two most common indications for a 1.5VR are a small pulmonary ventricle and a dilated poorly functioning pulmonary ventricle. Extension of 1.5VR to patients undergoing anatomical repair for congenitally corrected transposition of great arteries, straddling tricuspid valves, and severe Ebstein's anomaly has facilitated biventricular repair with decreased mortality. We reviewed the relevant literature on this subject in detail and describe its rationale, indications and its early and late results.

The hemi-Mustard, bidirectional Glenn and Rastelli procedures for anatomical repair of congenitally corrected transposition of the great arteries/left ventricular outflow tract obstruction with positional heart anomalies†

OBJECTIVES

The hemi-Mustard and bidirectional Glenn (BDG) procedures combined with the Rastelli procedure have been applied to selected cases of congenitally corrected transposition of the great arteries (ccTGA) for potential benefit over the classic atrial switch procedure. The aim of this study was to analyse our experience with the hemi-Mustard, BDG and Rastelli procedures as an anatomical correction for patients with ccTGA/left ventricular outflow tract obstruction (LVOTO) with positional heart anomalies.

METHODS

In this retrospective study, 31 consecutive patients with corrected transposition underwent the hemi-Mustard/BDG procedures with the Rastelli operation between 2011 and 2015. The median age was 5.4 (range: 0.75-12) years. Positional anomalies were present in all patients. Eleven patients underwent BDG initially; they then had the second-stage hemi-Mustard and Rastelli procedures; 'one-stage repair' (hemi-Mustard/BDG and the Rastelli procedures) was performed in 20 cases.

RESULTS

There were no in-hospital deaths, and 3 patients received a pacemaker. One patient had an atrial baffle obstruction that was observed in the early postoperative period; 7 patients had prolonged pleural effusions that developed more frequently in the one-stage repair group (7/20 vs 0/11, P =  0.033). During the mean follow-up of 3.3 years, 1 late death was noted, and no conduit replacements were required. Twenty-five (83.3%) patients are in New York Heart Association classes I and II at the latest follow-up.

CONCLUSIONS

Hemi-Mustard, BDG and the Rastelli procedures are technically feasible for correction of ccTGA/left ventricular outflow tract obstruction (LVOTO) and cardiac malposition. Nevertheless, postoperative pleural effusion is the most prevalent complication in the one-stage repair. Two-stage repair may reduce the risk of pleural effusion-related complications.

Biventricular repair versus uni-ventricular repair for pulmonary atresia with intact ventrical septum: A systematic review

The management of pulmonary atresia with intact ventricular septum (PA/IVS) remains controversial. The goal of separating systematic and pulmonary circulation can be achieved by biventricular or uni-ventricular (Fontan or one and a half ventricle repair) strategies. Although outcomes have been improved, these surgical procedures are still associated with high mortality and morbidity. An optimal strategy for definitive repair has yet to be defined. We searched databases for genetically randomized controlled trials (RCTs) comparing biventricular with uni-ventricular repair for patient with PA/IVS. Data extraction and quality assessment were performed following the guidelines of the Cochrane Collaboration. Primary outcome measures were overall survival, and secondary criteria included exercise function, arrhythmia-free survival and treatment-related mortality. A total number of 669 primary citations were screened for relevant studies. Detailed analysis revealed that no RCTs were found to adequately address the research question and no systematic meta-analysis would have been carried out. Nevertheless, several retrospective analyses and case series addressed the question of finding right balance between biventricular and uni-ventricular repair for patient with PA/IVS. In this review, we will discuss the currently available data.

17-year experience in surgical management of congenitally corrected transposition of the great arteries: a single-centre's experience

OBJECTIVES

We report our surgical experience in congenitally corrected transposition of great arteries (CCTGAs) and the long-term follow-up result.

METHODS

From January 1995 to February 2012, 56 patients with CCTGA received definite surgical repair; 15 patients received conventional repair (Group I), 18 patients received anatomical repair (Group II) and 23 patients received single ventricular palliation (Group III). They were followed for early and late mortality, long-term survival, postoperative morbidity and reintervention or reoperation.

RESULTS

The overall survival rate was 80% at 16 years in Group I, 53% at 13 years in Group II and 100% at 13 years in Group III. After excluding the early surgical mortality, the long-term survival rate was 92% at 16 years in Group I, 64% at 13 years in Group II and 100% at 13 years in Group III. Patients with significant tricuspid valve regurgitation showed the worst outcome after surgery.

CONCLUSIONS

Our series showed good results with single ventricular palliation (SVP) in CCTGA with complex anatomy, but the long-term result should be followed. Anatomical repair is the choice of operation only for those with favourable anatomy. The more complicated intracardiac repair may result in late left ventricular outflow tract obstruction, various degrees of atrioventricular block, systemic or pulmonary venous return obstruction and the lack of an ideal conduit (e.g. homograft) for Rastelli reconstruction. Therefore, we preferred SVP in patients with complex and unfavourable anatomy.

Repairing the tricuspid valve in congenital heart diseases other than Ebstein's

The tricuspid valve is being increasingly recognised as an important safeguard to the heart with congenital heart disease. Both structural anomalies of the valve and functional burdens from other malformations of the right heart can lead to major haemodynamic consequences both upstream and downstream. The indications to surgically intervene on the tricuspid valve are evolving and vary depending on the malformation. The extant surgical techniques and their applications to corresponding frequent congenital anomalies of the tricuspid valve are reviewed.

NUMERICAL STUDY OF BIDIRECTIONAL GLENN WITH UNILATERAL PULMONARY ARTERY STENOSIS

Purpose: Hypoplastic left heart syndrome (HLHS) is a congenital heart disease and is usually associated with pulmonary artery stenosis. The superior vena cava-to-pulmonary artery (bidirectional Glenn) shunt is used primarily as a staging procedure to the total cava-to-pulmonary connection for single-ventricle complex. When HLHS coexists with pulmonary artery stenosis, the surgeons then face a multiple problem. This leads to high demand of optimized structure of Glenn surgery. The objective of this article is to investigate the influence of various anastomotic structures and the direction of superior vena cava (SVC) in Glenn on hemodynamics under pulse inflow conditions and try to find an optimal structure of SVC in Glenn surgery with unilateral pulmonary artery stenosis.

Method: First, 3D patient-specific models were constructed from medical images of a HLHS patient before any surgery by using the commercial software Mimics, and another software Free-form was used to deform the reconstructed models in the computer. Four 3D patient-specific Glenn models were constructed: model-1 (normal Glenn), model-2 (lean the SVC back to the stenotic pulmonary artery), model-3 (lean the SVC towards the stenotic pulmonary artery), model-4 (add patch at junction of the SVC toward stenosis at pulmonary artery). Second, a lumped parameter model (LPM) was established to predict boundary conditions for computational fluid dynamics (CFD). In addition, numerical simulations were conducted using CFD through the finite volume method. Finally, hemodynamic parameters were obtained and evaluated.

Results: It was showed that model-4 have relatively balanced vena cava blood perfusion into the left pulmonary artery (LPA) and right pulmonary artery (RPA), this may be due to less helical flow and the patch at junction of the SVC. Near stenosis of pulmonary artery, model-4 performed with the higher wall shear stress (WSS), which would benefit endothelial cell function and gene expression. In addition, results showed that model-4 performed with the lower oscillatory shear index (OSI) and wall shear stress gradient (WSSG), which would decrease the opportunity of vascular intimal hyperplasia.

Conclusion: It is benefited that surgeons adds patch at junction of the SVC towards stenosis at pulmonary artery. These results can impact the surgical design and planning of the Glenn surgery with unilateral pulmonary artery stenosis.

One and a half ventricle repair in association with tricuspid valve repair according to "peacock tail" technique in patients with Ebstein's malformation and failing right ventricle

OBJECTIVES

The aim of this study was to evaluate the outcome in a series of patients with Ebstein's anomaly and a failing right ventricle (RV) undergoing tricuspid valve (TV) repair and bidirectional Glenn cavopulmonary anastomosis (BDG).

MATERIALS AND METHOD

Between January 2006 and September 2013, 11 consecutive patients diagnosed with severe forms of Ebstein's anomaly and a failing RV underwent TV surgery and BDG. The mean age was 16.5 ± 7 years. Most frequently found symptoms were cyanosis, dyspnea, and arrhythmias. The azygos or hemiazygos veins were left open. The TV was repaired using the "peacock tail" technique, which consisted of total detachment of the anterior and posterior leaflets of the TV and rotation in both directions reimplanting them to the true annulus. The mean follow-up was 3.8 ± 2.4 years (range three months to six years).

RESULTS

Hospital mortality was 9% (one patient). TV repair was possible in 10 patients. None of the patients had AV block postoperatively. At one year after surgery, the indexed RV and RA diameter were reduced significantly versus the preoperative data (p = 0.003 and p < 0.001). The mean TVR and indexed TV area were 1.2 ± 0.42 and 1.6 ± 0.6 (mm/m2), significantly lower than preoperatively (p = 0.001 and p = 0.008, respectively). The mean NYHA functional class, SaO2 , and cardiothoracic ratio were significantly improved.

CONCLUSIONS

The peacock tail technique for TV repair in combination with BDG in patients with Ebstein's malformation and depressed RV function results in TV preservation, a low incidence of recurrent regurgitation, favorable functional status and RV function, and resolution of cyanosis.

Intrapulmonary shear stress enhancement: a new therapeutic approach in pulmonary arterial hypertension

OBJECTIVE

Pulmonary arterial hypertension (PAH) is a dysfunctional endothelium disease with increased pulmonary vascular resistance (PVR) and poor prognosis. Current therapies are still insufficient. Here we propose a new pulsatile device as a more effective tool for PAH management compared with traditional treatments.

MATERIALS AND METHODS

Twelve piglets (10.3 ± 3.8 kg) were given either intrapulmonary pulsatile [P (n = 6)] or nonpulsatile [NP (n = 6)] tadalafil treatment. After median sternotomy and heparin injection (250 IU/kg), both groups underwent aorto-pulmonary surgical shunt for 1 h. During a second 1 h period in group P, a catheter prototype, driven by a small ventilator, was introduced into the pulmonary trunk and pulsated intermittently at 110 bpm irrespective of heart rate (90.6 ± 10.74 bpm). In group NP, tadalafil was given orally (1 mg/kg).

RESULTS

Hemodynamics and cardiac output (CO) were significantly (p < 0.05) improved in group P compared with group NP: CO was 0.56 ± 0.0.26 versus 0.54 ± 0.11 (L/min), respectively. Mean pulmonary artery pressure (PAP) was decreased in group P compared with group NP: PAP was 9.6 ± 2.97 versus 32.2 ± 5.07, respectively. Vascular resistances (dynes.s.cm(-5)/kg) were significantly lower in group P versus group NP: pulmonary resistance was 85 ± 42.12 versus 478 ± 192.91 and systemic resistance was 298.8 ± 172.85 versus 1301 ± 615.79, respectively. Using Western blot analysis, endogenous NO synthase expression in PA segments was nonsignificantly (p > 0.05) greater in group P (0.81 ± 0.78) versus (0.62 ± 0.35) group NP.

CONCLUSION

Induced with an appropriate device, intrapulmonary shear stress-mediated endothelial function enhancement provides a more effective nearly physiological therapy for PAH.

The role of the Fontan operation in the treatment of congenitally corrected transposition of the great arteries

Congenitally corrected transposition of the great arteries (ccTGA) is a complex cardiac anomaly with an unfavorable natural history. Surgical treatment has been available for over 50 years. Initial procedures used for ccTGA did not correct atrio-ventricular discordance, leaving the right ventricle in systemic position. In the past two decades anatomic repair has been considered to be a better option. Many cases subjected to anatomic repairs would also be suitable for the Fontan strategy, which probably has a lower initial risk. The rationale for use of the Fontan operation in management of congenitally corrected transposition is discussed in this review, with comparisons to other strategies.

Selective right ventricular unloading and novel technical concepts in Ebstein's anomaly

BACKGROUND

Favorable outcomes in Ebstein's anomaly are predicated on tricuspid valve competence and right ventricular function. Successful valve repair should be aggressively pursued to avoid the morbidity of prosthetic tricuspid valve replacement. We report our experience with valve-sparing intracardiac repair, emphasizing novel concepts and techniques of valve repair supplemented by selective bidirectional Glenn (BDG).

METHODS

Between June 1993 and December 2008, 57 nonneonatal patients underwent Ebstein's anomaly repairs. The median age at operation was 8.1 years. All were symptomatic in New York Heart Association (NYHA) functional class II (n = 38), III (n = 17), or IV (n = 1). Preoperatively, 26 had mild or moderate cyanosis at rest. We used a number of valve reconstructive techniques that differed substantially from those currently described. BDG was performed in 31 patients (55%) who met specific criteria.

RESULTS

No early or late deaths occurred. At the initial repair, 3 patients received a prosthetic valve. Four patients required reoperation for severe tricuspid regurgitation. Repeat repairs were successful in 2 patients. At follow-up (range, 3 months to 6 years), all patients were acyanotic and in NYHA class I. Tricuspid regurgitation was mild or less in 49 (86%) and moderate in 6 (11%). Freedom from a prosthesis was 91% (52 of 57).

CONCLUSIONS

Following a protocol using BDG for ventricular unloading in selected patients with Ebstein's anomaly can achieve a durable valve-sparing repair using the techniques described. Excellent functional midterm outcomes can be obtained with a selective one and a half ventricle approach to Ebstein's anomaly.

Bidirectional Glenn shunt as an adjunct to surgical repair of congenital heart disease associated with pulmonary outflow obstruction: relevance of the fluid pressure drop-flow relationship

A bidirectional Glenn shunt (BGS) was successfully incorporated into a two-ventricle repair for 10 patients (age, 3-17 years) who had congenital heart disease associated with severe pulmonary outflow obstruction. The BGS was used to volume-unload the pulmonary ventricle faced with residual outflow obstruction, thereby avoiding the need for insertion of a ventricle-to-pulmonary artery conduit. Transthoracic Doppler flow velocity analysis was used to determine transpulmonary peak systolic pressure drops as a measure of obstruction. Preoperative values ranged from 70 to 100 mmHg, and postoperative values ranged from less than 10 to 16 mmHg. At this writing, all patients are doing well 15 to 52 months after surgery. To gain further insight into the reduced pressure drop that may be achieved by decreasing flow rate across obstruction, a computer-based description of fluid flow was used to simulate blood traversing circumferentially narrowed passages. Overall pressure drops and associated flow energy losses were determined from numeric solutions (using finite-element analysis) to the Navier-Stokes equations for the proposed fluid reactions. Pressure drops and flow energy losses were found to decrease dramatically as flow rate was progressively reduced. For selected patients, a BGS can be an effective adjunct to the surgical treatment of pulmonary outflow obstruction. This approach avoids the use of a ventricle-to-pulmonary artery conduit, and thus the inevitable need in most patients for reoperations because of somatic growth, conduit failure, or both.

Results with continuous cardiopulmonary bypass for the bidirectional cavopulmonary anastomosis

OBJECTIVE

Some centres have proposed creating the bidirectional cavopulmonary anastomosis without cardiopulmonary bypass, while others continue to use deep hypothermic circulatory arrest. The purpose of this review is to evaluate the results of using continuous cardiopulmonary bypass with moderate hypothermia, perhaps the most commonly used of the three techniques for this procedure.

METHODS

Between 1990 and 2005, 114 patients, having a mean age of 1.58 years, with a median age of 8 months, and ranging from 3 months to 16 years, underwent creation of either a unilateral cavopulmonary anastomosis, in 94 cases, or bilateral anastomoses in 20 cases. All had continuous cardiopulmonary bypass with moderate hypothermia at 32 degrees Celsius, with 24 also having aortic cross-clamping with cardioplegia for simultaneous intracardiac procedures. Interrupted absorbable sutures were used to create the anastomosis in 105 patients.

RESULTS

Perioperative mortality was 5%, with 6 of the patients dying. The mean period of cardiopulmonary bypass for an isolated anastomosis was 91 minutes, with a range from 44 to 160 minutes. In 10 patients (8.8%), it was necessary to place a graft to augment the anastomosis. The average postoperative length of stay was 7.9 days for those undergoing an isolated unilateral anastomosis, and 16.4 days for patients undergoing combined cardiac operations. We have now created the Fontan circulation in 79 of the patients, at an average interval from the bidirectional cavopulmonary anastomosis of 2.1 plus or minus 1.14 years. In 76 patients, we performed postoperative angiograms, and none revealed any stenoses.

CONCLUSIONS

The bidirectional cavopulmonary anastomosis can be performed successfully with continuous cardiopulmonary bypass and moderate hypothermia with a beating heart, avoiding circulatory arrest. The use of interrupted and absorbable sutures was not associated with any late anastomotic stenosis.

State of the art of cardiac surgery in patients with congenital heart disease

During the last 20 years, pediatric cardiac surgery has been characterized by important changes, with reductions in surgical mortality and the achievement of complete repair at an earlier age, thus avoiding multiple procedures and strongly ameliorating the global outcome of these patients. In this review, we describe the actual trends in the surgical treatment of cardiac malformations. We analyze two groups of patients: in the first group (septal defects, tetralogy of Fallot, transposition of the great arteries, aortic stenosis and coarctation) the indications are well established and the goal is represented by a lessening of the surgical trauma and post-operative morbidity, with stable results in the follow-up. In the second group (univentricular heart, pulmonary atresia and intact ventricular septum, double discordance, conduit, hypoplastic left heart syndrome), the lesions are still considered complex and submitted to ongoing experimental and clinical research, in order to improve the post-surgical history of these diseases.

The classical and the one-and-a-half ventricular options for surgical repair in patients with discordant atrioventricular connections

The classical option for surgical repair in patients with congenitally corrected transposition takes advantage of the physiologic correction provided by nature. At the end of the surgical procedures, however, the morphologically right ventricle remains as the systemic ventricle. Surgical intervention is essentially the correction of associated lesions, including closure of ventricular septal defects, pulmonary valvotomy, placement of a conduit from the morphologically left ventricle to the pulmonary arteries, replacement of the morphologically tricuspid valve, and placement of pacemakers for third degree atrioventricular block. For many years, the classical approach was the “standard” surgical approach.1–4More recently, newer alternatives have become available, including forms of anatomic repair, the “one-and-a half” ventricular option, and conversion to the Fontan circulation. The goal of anatomic repair is to craft connections such that the morphologically left ventricle becomes the systemic ventricle. Surgical techniques that accomplish this are a Rastelli procedure combined with an atrial baffle,5and the combination of an arterial switch with an atrial baffle, be it a Mustard or Senning procedure.6

Physiologic versus anatomic repair of congenitally corrected transposition of the great arteries: meta-analysis of individual patient data

The objective of this meta-analysis of individual patients' data was to compare the immediate outcomes of anatomic and physiologic repair of congenitally corrected transposition of the great arteries. Eleven nonrandomized studies, involving 124 patients, met the inclusion criteria for this review. The Rastelli type anatomic repair and the era of surgery were significantly related to the outcome in different tested models. Entering all variables into the logistic regression model showed a significant protective effect of the Rastelli type anatomic repair (odds ratio = 0.05, 95% confidence interval: 0.01, 0.50, p = 0.02).

Surgical management of unbalanced atrioventricular canal defect

Approximately 10% of endocardial cushion defects exhibit unbalance at the atrioventricular inlet. When the atrioventricular valve sits more over one ventricle than the other, the contralateral ventricle is typically hypoplastic. Surgical intervention for unbalanced atrioventricular canal has a much higher morbidity and mortality than for the balanced form of the defect. With unbalanced atrioventricular canal to the right, no universal criteria are in place to choose single versus biventricular repair. In many cases, risk factors have been extrapolated from other lesions with left ventricular hypoplasia. Even if biventricular repair is successful, the reoperation rate is high for this lesion. Little data exist in the literature regarding left unbalanced atrioventricular canal. In general, right ventricular hypoplasia is better tolerated than left ventricular hypoplasia, and biventricular repair is usually possible. If cyanosis or high systemic venous pressure results, the one and one half ventricle repair (biventricular repair with bidirectional Glenn anastomosis) is an option. This article reviews the present understanding of unbalanced atrioventricular canal and discusses diagnostic and surgical strategies for this complex lesion.

The double switch for atrioventricular discordance

Conventional surgery for atrioventricular discordance usually associated with ventricular arterial discordance leaves the morphologic right ventricle in the systemic circulation. Long-term follow-up results with this approach reveal a high incidence of right ventricular failure. The double switch procedure was introduced to restore the morphologic left ventricle to the systemic circulation. This operation is performed in two main ways: the atrial-arterial switch and the atrial switch plus Rastelli procedure. This double switch approach has been successful at least in the medium term in abolishing morphologic right ventricular failure and its associated tricuspid valve regurgitation. In the atrial-arterial switch group, there is an incidence of morphologic left ventricular dysfunction, sometimes associated with neoaortic valve regurgitation, and the minority of cases need aortic valve replacement. The long-term function of the morphologic left ventricle and the aortic valve need careful surveillance in the future. The atrial-Rastelli group of patients has not in the medium term shown evidence of ventricular dysfunction but will require change on a regular basis of their ventricular to pulmonary artery valved conduits.

The beneficial effects of total cavopulmonary conversion and arrhythmia surgery for the failed Fontan

Postoperative Fontan patients can develop hemodynamic abnormalities and refractory atrial arrhythmias resulting in significant morbidity and mortality. We present our experience with total cavopulmonary artery conversion and arrhythmia surgery. Between 1994 and 2001, 41 patients underwent total cavopulmonary artery conversion and arrhythmia surgery. Significant hemodynamic lesions were repaired concomitantly: aortic aneurysm (n=1), atrioventricular valve insufficiency (n=8), and pulmonary artery stenosis (n=9). Thirty-five patients were in New York Heart Association class III or IV. Mean age at original Fontan was 7.5+/-6.5 years, at Fontan conversion, 18.7+/-9.0 years. Arrhythmia surgery for atrial re-entry tachycardia evolved from isthmus cryoablation (n=10) to right-sided maze (n=17). Maze-Cox III was used for 14 patients with atrial fibrillation. Atrial (n=34) and dual chamber (n=5) pacemakers were placed. Mortality and reoperation for bleeding rates are 0%. Chest tubes were removed on postoperative day 9.0+/-6.0. Mean hospital stay was 11.8+/-6.6 days. Three patients required cardiac transplantation at 8 days, 9 months, and 33 months postoperatively. There was one long-term death from acute myocardial infarction 2 years postoperatively. For the entire series, arrhythmia recurrence is 12.2% (5/41). Only 9.8% of patients (4/41) receive chronic antiarrhythmic medications; these patients were among the first eight in the series. Most patients are in New York Heart Association I or II. Bruce protocol in 12 patients showed increased tolerance (P<.05) Total cavopulmonary artery conversion with concomitant arrhythmia surgery is excellent therapy for patients with failed Fontan. It is safe, improves New York Heart Association class, improves exercise tolerance, and the incidence of recurrent arrhythmias is low.

Congenitally Corrected Transposition of the Great Arteries: Current Treatment Options

Congenitally corrected transposition of the great arteries is a relatively rare cardiac malformation characterized by atrioventricular and ventriculoarterial discordance. This double discordance results in a physiologically corrected circulation with the morphologic right ventricle (RV) serving as the systemic pump. Associated anomalies are present in approximately 98% of cases and include most commonly ventricular septal defect, pulmonary stenosis, and anomalies of the systemic atrioventricular valve (SAVV). Conduction abnormalities are common as well, predisposing these patients to the development of complete heart block. The management of these patients is primarily determined by the presence and severity of the associated anomalies. Conventional repair, which leaves the morphologic RV as the systemic ventricle, has resulted in high incidence of tricuspid regurgitation (TR) and progressive dysfunction of the RV. In the majority of patients, congestive heart failure secondary to RV dysfunction occurs by the fifth or sixth decade. The cause and effect relationship between TR and RV dysfunction remains to be determined. The advent of the Double Switch operation, which restores the morphologic left ventricle (LV) as the systemic ventricle, has yielded favorable outcomes at early follow-up. This procedure should be applied in young patients to achieve optimal results. Retraining the LV by pulmonary artery banding is associated with high morbidity and mortality when attempted after infancy or early childhood. Long-term follow-up is needed to evaluate the potential superiority of this procedure and the incidence of rhythm, baffle, and conduit complications for this management option.

Total cavopulmonary conversion and maze procedure for patients with failure of the Fontan operation

OBJECTIVES

Hemodynamic abnormalities and refractory atrial arrhythmias in patients late after the Fontan operation result in significant morbidity and mortality. We review our experience with conversion to total cavopulmonary artery connections and arrhythmia surgery.

METHODS

Between 1994 and 2001, 40 patients underwent Fontan conversion and arrhythmia surgery. Significant hemodynamic lesions such as aortic aneurysm (n = 1), atrioventricular valve insufficiency (n = 8), and pulmonary arterioplasty (n = 9) were repaired concomitantly. Thirty-four patients were in New York Heart Association class III or IV. Mean age at the original Fontan operation was 7.5 +/- 6.5 years and mean age at Fontan conversion was 18.7 +/- 9.0 years. Arrhythmia surgery has evolved from isthmus cryoablation in 10 patients to right-sided maze in 16 patients for atrial reentry tachycardia. The maze-Cox III operation was used for 14 patients with atrial fibrillation. Atrial (n = 33) and dual-chamber (n = 5) pacemakers were placed.

RESULTS

There has been no early mortality. Chest tubes were removed on postoperative day 9.0 +/- 6.0. Hospital stay was 11.8 +/- 6.6 days. Three patients required cardiac transplantation at 8 days, 9 months, and 33 months postoperatively. There was 1 death 2 years postoperatively from acute myocardial infarction. For the entire series, arrhythmia recurrence is 12.5%, with only 10% of patients receiving long-term antiarrhythmic medications; these patients were among the first 8 patients in our series. Most patients are in New York Heart Association class I or II. Bruce protocol in 12 patients showed increased tolerance (P <.05).

CONCLUSIONS

Fontan conversion to total cavopulmonary connection with concomitant arrhythmia surgery is excellent therapy for patients whose Fontan repair has failed. Fontan conversion is safe, improves New York Heart Association class, improves exercise tolerance, and has a low incidence of recurrent arrhythmias.

One and one half ventricle repairs

Patients with functionally or anatomically borderline pulmonary ventricles can be managed by a biventricular repair, a Fontan procedure, or by an intracardiac repair in association with a cavopulmonary anastomosis. The latter repair is known as a one and one half ventricle repair. Extending the limits of a biventricular repair can be associated with a high early mortality. The Fontan is associated with late failure. One and one half ventricle repairs are an attempt to reduce early risk and late failure while still achieving separate pulmonary and systemic circulations. The two most common reasons for a one and one half ventricle repair are a small pulmonary ventricle and a dilated poorly functioning pulmonary ventricle. Estimated ventricular volumes of 30% to 80% and z values as small as -10 have been successfully repaired with the one and one half ventricle approach. Ebstein's anomaly is the most common situation where dilated and poorly functioning pulmonary ventricles are treated with a one and one half ventricle repair. There are also special situations where the one and one half ventricle repair is logical. Mortality has ranged from 0% to 12%. No intermediate term sequelae of protein loosing enteropathy, atrial arrhythmias, or pulmonary arteriovenous fistula have been identified. Successful one and one half ventricle repairs have primarily been performed for small pulmonary ventricles and poorly functioning pulmonary ventricles such as those seen with Ebstein's anomaly. Intermediate term follow up has been favorable when compared to the Fontan circulation. Copyright 2000 by W.B. Saunders Company

Advances in pediatric cardiovascular surgery: anatomic reconstruction of the left ventricular outflow tract in transposition of the great arteries with pulmonic valve abnormalities

In the past years, advances in pediatric cardiovascular surgery have occurred in many areas with some of the greatest strides being made in complex repairs in younger age groups. Aggressive early corrections while higher risk, may in the long run provide a child with a normal anatomic heart, and corresponding myocardial growth and physiology.

Congenital Heart Surgery Nomenclature and Database Project: transposition of the great arteries

The extant nomenclature for transposition of the great arteries (TGA) is reviewed for the purposes of establishing a unified reporting system. The subject was debated and reviewed by members of the STS-Congenital Heart Surgery Database Committee and representatives from the European Association for Cardiothoracic Surgery. All efforts were made to include relevant nomenclature categories including synonyms where appropriate. The general categories of TGA are: TGA with intact ventricular septum, TGA with ventricular septal defect (VSD) and TGA with VSD and left ventricular outflow tract obstruction (LVOTO). A comprehensive database set is presented which is based on a hierarchical scheme. Data are entered at various levels of complexity and detail that can be determined by the clinician. A detailed hierarchical system is described herein for classification of the coronary artery anatomy associated with TGA. These data can lay the foundation for comprehensive risk stratification analyses. A minimum database set is also presented which will allow for data sharing and would lend itself to basic interpretation of trends.