Early changes in ventricular septal defect size and ventricular geometry in the single left ventricle after volume-unloading surgery

Comparing palliation strategies for single-ventricle anatomy with transposed great arteries and systemic outflow obstruction

Objective

Patients with complex single-ventricle anatomy with transposed great arteries and systemic outflow obstruction (SV-TGA-SOO) undergo varied initial palliation with ultimate goal of Fontan circulation. We examine a longitudinal experience with multiple techniques, including the largest published cohort following palliative arterial switch operation (pASO), to describe outcomes and decision-making factors.

Methods

Neonates with SV-TGA-SOO who underwent initial surgical palliation from 1995 to 2022 at a single institution were retrospectively reviewed.

Results

In total, 71 neonates with SV-TGA-SOO underwent index surgical palliation at a median age of 7 days (interquartile range, 6-10) by pASO (n = 23), pulmonary artery band (PAB) with or without arch repair (n = 25), or modified Norwood with Damus-Kaye-Stansel aortopulmonary amalgamation (n = 23). Single-ventricle pathology included double-inlet left ventricle (n = 37, 52%), tricuspid atresia (n = 27, 38%), and others (n = 7, 10%). All mortalities (n = 5, 7%) occurred in the first interstage period after PAB (n = 3) and Norwood (n = 2). Subaortic obstruction in the PAB group was addressed by operative resection (n = 10 total, 7 at index operation) and/or delayed aortopulmonary amalgamation (n = 13, 52%). Two patients with pASO (9%) had early postoperative coronary complications, 1 requiring operative revision. Median follow-up for survivors was 10.4 years (interquartile range, 4.5-16.6 years). Comparing patients by their initial palliation type, notable significant differences included size of bulboventricular foramen, weight at initial operation, operation duration, postoperative length of stay, time to second-stage palliation, multiple pulmonary artery reinterventions, and left pulmonary artery interventions. There were no significant differences in overall survival, Fontan completion, reintervention-free survival in the first interstage period, pulmonary artery reintervention-free survival, long-term systemic valve competency, or ventricular dysfunction.

Conclusions

Excellent mid- to long-term outcomes are achievable following neonatal palliation for SV-TGA-SOO via pASO, PAB, and modified Norwood, with comparable survival and Fontan completion. Initial palliation strategy should be individualized to optimize anatomy and physiology for successful Fontan by ensuring an unobstructed subaortic pathway and accessible pulmonary arteries. pASO is a reasonable strategy to consider for these heterogeneous lesions.

Contemporary risk factors for a longer hospital stay following bidirectional cavopulmonary anastomosis

BACKGROUND

Despite high survival after bidirectional cavopulmonary anastomosis, a considerable number of patients suffer significant post-operative morbidities related to prolonged length of stay.

METHODS

A single-center retrospective cohort study of all consecutive patients undergoing a first-time bidirectional cavopulmonary anastomosis from 2006 to 2019.

RESULTS

Prolonged length of stay was defined as hospital stay greater than the 75th percentile for our cohort. Of 195 patients who met inclusion criteria, the median post-operative length of stay was 8 days (interquartile range, 4-15 days). Prolonged length of stay was defined as greater than 15 days. In multivariate analysis, greater than mild systemic atrioventricular valve regurgitation (odds ratio 3.7, 95% CI 1.05-13.068, p = 0.04), longer length of stay after the initial palliative procedure (odds ratio 1.028, 95% CI 1.004-1.05, p = 0.02), and pre-operative higher superior vena cava oxygen saturation (odds ratio 0.922, 95% CI 0.85-0.99, p = 0.04) maintained statistical significance as independent risk and protective factors for prolonged length of stay. A one-level increase in the severity of pre-operative systemic atrioventricular valve regurgitation was associated with a multiplicative change in the odds ratio of prolonged length of stay of 5.45 (p = 0.005) independent of the severity of systemic ventricular dysfunction.

CONCLUSION

Pre-operative characteristics with greater than mild systemic atrioventricular valve regurgitation, longer length of stay after the initial palliative procedure, and lower superior vena cava oxygen saturation were associated with prolonged length of stay after a first-time bidirectional cavopulmonary anastomosis.

Modified Damus-Kaye-Stansel Connection for Systemic Outflow Tract Obstruction After Fontan Operation

Late systemic outflow tract obstruction following completion of the Fontan palliation is rarely seen and is a difficult problem to treat. Absence of the main pulmonary trunk and pulmonary valve at this stage makes a conventional Damus-Kaye-Stansel connection difficult to achieve. We report the case of a 37-year-old female who underwent Fontan completion as an adult and subsequently presented with systemic outflow tract obstruction. A valved conduit was interposed between the native pulmonary annulus and the ascending aorta to create a modified Damus-Kaye-Stansel type connection.

Failure of Cellularization of Ventriculotomy Patch Leading to Right Ventricular Pseudoaneurysm

Enlargement of the bulboventricular foramen (BVF) in double-inlet left ventricle or the ventricular septal defect (VSD) in tricuspid atresia with transposition of the great arteries is one approach for prevention or treatment of systemic ventricular outflow obstruction. Most often, BVF/VSD restriction is bypassed preemptively or addressed directly at the time of Glenn/Fontan procedures as part of staged univentricular palliation. We describe a patient who underwent enlargement of a restrictive VSD during Fontan completion and subsequently presented with an asymptomatic pseudoaneurysm of the right ventricle at the ventriculotomy site.

The Superior Cavopulmonary Connection: History and Current Perspectives

The development of the superior cavopulmonary connection is a rich illustration of international influences in congenital cardiac surgery. The bidirectional Glenn and hemi-Fontan procedures have improved survival as both definitive and staged functional single ventricle palliation. The optimal timing of the second-stage superior cavopulmonary procedures varies by center but for low- and intermediate-risk patients, this may be within three to six months after the Norwood procedure. The list of risk factors continues to grow but the most frequently cited factors include atrioventricular valve regurgitation, decreased ventricular function, need for reintervention, and failure to attain nutritional and growth goals. Ongoing prospective, multi-institutional studies, particularly those fostered internationally by the World Society for Pediatric and Congenital Heart Surgery and other associations, will hopefully provide further clarification of the complex management issues related to patients with functional single ventricle physiology.

Long-Term Outcome of Direct Relief of Subaortic Stenosis in Single Ventricle Patients

Background:

Single ventricle patients with unrestrictive pulmonary blood flow and (potential) subaortic stenosis are challenging to manage and optimal surgical strategy is unknown. Direct relief of subaortic stenosis by enlargement of the ventricular septal defect and/or subaortic chamber has generally been replaced by a Damus-Kaye-Stansel or Norwood procedure due to concerns of iatrogenic heart block, reobstruction, or ventricular dysfunction. Studies reporting long-term outcome after the direct approach are limited. The aim of our study was to describe and analyze our experience with direct relief of subaortic stenosis in single ventricle patients.

Methods:

Demographic data, characteristics, and pre-operative, operative and outcome details were collected for children undergoing direct relief of subaortic stenosis between 1989 and 2016.

Results:

Twenty-three patients (median age: 7.4 months, range: 10 days to 5.5 years) underwent direct relief of subaortic stenosis. Complete follow-up was available for all patients (median: 15.6 years, range: 34 days to 26.3 years). Seven (30%) patients had recurrence of subaortic stenosis. One (4%) patient developed complete heart block and one patient developed moderate ventricular dysfunction. Five (50%) patients developed a (pseudo)aneurysm at site of the patch and ventriculotomy. There were two perioperative deaths. Eighty-six percent of patients underwent a successful Fontan procedure.

Conclusions:

Direct relief of subaortic stenosis is associated with a substantial risk of reobstruction and patch (pseudo)aneurysm formation. However, risk of heart block is low and long-term outcome is good with the majority of patients reaching Fontan completion. In our opinion, the direct approach appears to be a good and relatively simple procedure in selected cases for the treatment of subaortic stenosis.

The Effect of the Superior Cavopulmonary Anastomosis on Ventricular Remodeling in Infants with Single Ventricle

BACKGROUND

Infants with single ventricular physiology have volume and pressure overload that adversely affect ventricular mechanics. The impact of superior cavopulmonary anastomosis (SCPA) on single left ventricles versus single right ventricles is not known.

METHODS

As part of the Pediatric Heart Network placebo-controlled trial of enalapril in infants with single ventricular physiology, echocardiograms were obtained before SCPA and at 14 months and analyzed in a core laboratory. Retrospective analysis of the following measurements included single ventricular end-diastolic volume (EDV), end-systolic volume (ESV), mass, mass-to-volume ratio (mass/volume), and ejection fraction. Qualitative assessment of atrioventricular valve regurgitation and assessment of diastolic function were also performed.

RESULTS

A total of 156 participants underwent echocardiography at both time points. Before SCPA, mean ESV and mass Z scores were elevated (3.4 ± 3.7 and 4.2 ± 2.9, respectively) as were mean EDV and mass/volume Z scores (2.1 ± 2.5 and 2.0 ± 2.9, respectively). EDV, ESV, and mass decreased after SCPA, but mass/volume and the degree of atrioventricular valve regurgitation did not change. Subjects with morphologic left ventricles demonstrated greater reductions in ventricular volumes and mass than those with right ventricles (mean change in Z score: left ventricular [LV] EDV, -1.9 ± 2.1; right ventricular EDV, -0.7 ± 2.5; LV ESV, -2.3 ± 2.9; right ventricular ESV, -0.9 ± 4.6; LV mass, -2.5 ± 2.8; right ventricular mass, -1.3 ± 2.6; P ≤ .03 for all). Approximately one third of patients whose diastolic function could be assessed had abnormalities at each time point.

CONCLUSIONS

Decreases in ventricular size and mass occur in patients with single ventricle after SCPA, and the effect is greater in those with LV morphology. The remodeling process resulted in commensurate changes in ventricular mass and volume such that the mass/volume did not change significantly in response to the volume-unloading surgery.

Management of the single ventricle and potentially obstructive systemic ventricular outflow tract

Multi-stage palliation is the current management strategy for the treatment of children with various single ventricle (SV) cardiac malformations. The success of this strategy depends on the presence of favorable anatomic and hemodynamic criteria. Several SV anomalies have the potential of developing systemic ventricular outflow tract obstruction (SVOTO) that might be evident early on or progress later after palliative surgeries. SVOTO could result in ventricular hypertrophy, impaired diastolic function and subendocardial ischemia with subsequent deleterious effects on the SV and disturbance of some of those criteria for a successful multi-stage palliation strategy. Careful identification of SV patients at risk of developing SVOTO and proper planning of the optimal palliation sequence beginning at the 1st stage procedure are vital factors that would affect long-term outcomes in those patients. In the current review, we describe the morphology of SV patients with potential SVOTO risk, surgical procedures that address potential or present SVOTO, and optimal timing of those procedures within the multi-stage palliation chain. We attempt to provide a treatment algorithm for various patients taking into consideration their unique anatomic and physiologic characteristics.

Tricuspid atresia with aortopulmonary window: challenges in achieving a balanced circulation

Tricuspid atresia and aortopulmonary window are rare congenital cardiac anomalies. The occurrence of both these anomalies in the same patient is extremely rare, with only 1 case reported in the literature. We report the surgical management of one such patient and discuss the management issues with respect to Stage 1 single ventricle palliation.

Efficacy of Damus-Kaye-Stansel procedure in patients with univentricular heart associated with ventriculo-arterial discordance and excessive pulmonary blood flow

Pulmonary artery banding (PAB) and ventriculo-arterial discordance (VAD) were reported to be risk factors of subaortic stenosis in univentricular heart. The aim of this study was to evaluate efficacy of Damus-Kaye-Stansel (DKS) anastomosis. Of all 89 patients undergoing total cavo-pulmonary connection (TCPC) in our center since April 1996, 38 had VAD with high pulmonary blood flow, and had received PAB. Twenty-one of 38 had undergone DKS anastomosis due to subaortic stenosis or due to morphological hypertrophy of the outlet septum (DKS group); the other 17 had not yet (no-DKS group). Percentage end-systolic volume of the systemic ventricle and percentage subaortic lesion in both groups significantly decreased after TCPC (P<0.01). Pressure gradient across systemic outflow tract after TCPC was low in both groups at rest. The gradient in DKS group did not differ from those in control group with ventriculo-arterial concordance (VAC) (P>0.1). Ventricular outflow tract after DKS anastomosis might behave like that of VAC even when dobutamine is loaded, suggesting that the anastomosis should be carried out in many patients with this entity even if stenosis across systemic ventricular outflow is not significant, considering possible stenosis in the future.

Pulmonary Arteriovenous Malformations in Heterotaxy Syndrome

We report a surgical approach using hepatic vein–to–azygos vein connection without cardiopulmonary bypass or deep hypothermic circulatory arrest in a patient with heterotaxy syndrome and interrupted inferior vena cava with persistence of pulmonary arteriovenous malformations (PAVMs) after previous Fontan completion. We advocate early performance of hepatic vein–to–azygos vein connection following the Kawashima operation for heterotaxy with functionally univentricular heart and interrupted inferior vena cava. We review the physiology of heterotaxy syndrome with congenital heart disease and justify our approach in the context of a review of previous surgical strategies used in this patient population.

Guidelines for the outpatient management of complex congenital heart disease

An increasingly complex group of children is now being followed as outpatients after surgery for congenital heart disease. A variety of complications and physiologic perturbations, both expected and unexpected, may present during follow-up, and should be anticipated by the practitioner and discussed with the patient and family. The purpose of this position article is to provide a framework for outpatient follow-up of complex congenital heart disease, based on a review of current literature and the experience of the authors.

Designing therapeutic strategies for patients with a dominant left ventricle, discordant ventriculo-arterial connections, and unobstructed flow of blood to the lungs

The palliation of the cyanotic child with a dominant morphologically left ventricle, discordant ventriculo-arterial connections, and obstruction to the pulmonary outflow tract has continued to evolve and mature. The evolution began in the early days of surgical palliation with the Blalock-Taussig shunt, extended to construction of cavopulmonary shunts, if required, and then to the Fontan procedure and its subsequent modifications. This journey took nearly 30 years to complete. There is increasing clinical data to document the beneficial effects of this approach, with ever-improving outcomes. Some aspects of the history of the cavopulmonary shunt have been previously reviewed in this journal and elsewhere, as have analysis of outcomes for some groups of patients considered for surgical completion of the Fontan circulation. While there has been some ongoing interest in ventricular septation since the early success of Sakakibara et al., this approach has largely been abandoned. Considerably more challenges and debate resonate in the surgical algorithms defined for patients whose hearts are characterized by a dominant left ventricle, discordant ventriculo-arterial connections, and unobstructed flow of blood to the lungs. This latter group will be the focus of this review, as will the aetiology of the myocardial hypertrophy that is particularly frequent in this group of patients, its clinical recognition, indeed its anticipation, and the multiple surgical strategies designed to prevent or treat it. All these manoeuvres are considered to optimise suitability for, and outcome from, creation of the Fontan circulation.

Outcome of patients with double-inlet left ventricle or tricuspid atresia with transposed great arteries

OBJECTIVES

We sought to determine the long-term outcomes and risk factors for mortality in patients with double-inlet left ventricle (DILV) or tricuspid atresia with transposed great arteries (TA-TGA).

BACKGROUND

Patients with DILV or TA-TGA are at risk of systemic outflow obstruction and a poor outcome. The impact of various management strategies on the long-term outcomes of these patients remains unknown.

METHODS

We reviewed the outcomes of 164 consecutive pediatric patients with DILV or TA-TGA who underwent surgical palliation between 1983 and 2002. Patients with a Holmes heart or heterotaxy syndrome or who were lost to follow-up (n = 24) were excluded. Risk factors for mortality or the need for orthotopic heart transplantation (OHT) were assessed by multivariate analysis.

RESULTS

There were 105 patients with DILV and 35 patients with TA-TGA. The overall mortality rate, including OHT, was 29%. Patients with DILV had a lower mortality rate than patients with TA-TGA (23% vs. 49%, p = 0.007). Multivariate analysis showed the presence of arrhythmia and pacemaker requirement as independent risk factors for mortality, whereas pulmonary atresia or stenosis and pulmonary artery banding were associated with decreased mortality. Gender, era of birth, aortic arch anomaly, and systemic outflow obstruction were not risk factors. The perioperative and overall mortality were similar between patients who underwent the Damus-Kaye-Stansel procedure beyond the neonatal period and those had subaortic resection.

CONCLUSIONS

The mortality of patients with DILV or TA-TGA remains high. The outcomes of these patients are influenced by restriction of pulmonary blood flow, arrhythmia, and pacemaker requirement. Surgical palliation to relieve systemic outflow obstruction is not associated with a poor outcome.

Outcome of staged surgical approach to neonates with single left ventricle and moderate size bulboventricular foramen

Neonates with double-inlet left ventricle or tricuspid atresia with transposed great arteries and a bulboventricular foramen (BVF) area <2 cm(2)/m(2) develop BVF obstruction. This study examined the outcome of neonates with BVF area between 1 and 2 cm(2)/m(2) whose BVF was bypassed after the neonatal period. We reviewed 29 neonates with double-inlet left ventricles (n = 18) or tricuspid atresia (n = 11) and transposed great arteries. The study group consisted of 9 patients with neonatal BVF areas of 1 to 2 cm(2)/m(2) who did not undergo repair of the BVF obstruction as a neonate. The comparison group consisted of 8 "ideal" patients without BVF obstruction. Precavopulmonary shunt data from cardiac catheterization and echocardiogram and outcomes of the cavopulmonary shunt were compared. Study group patients developed a mild BVF gradient (18 +/- 10 mm Hg by cardiac catheterization) by a mean of 7 months. Left ventricular wall thickness, however, remained in the normal range (4.2 +/- 0.3 mm) and was not statistically different from the comparison group (4.1 +/- 0.4 mm). No difference was found in the precavopulmonary mean pulmonary artery pressure (15 +/- 5 vs 15 +/- 6 mm Hg), transpulmonary gradient (8 +/- 4 vs 8 +/- 5 mm Hg), and left ventricular end-diastolic pressure (7 +/- 2 vs 8 +/- 3 mm Hg). One patient in the study group died from respiratory syncytial virus pneumonia while awaiting cavopulmonary shunt. Neither group had mortality from the cavopulmonary shunt. The lengths of hospital stay were comparable (8.3 +/- 3.7 vs 8.9 +/- 6.0 days). Thus, neonates with BVF area between 1 and 2 cm(2)/m(2) develop mild but hemodynamically insignificant BVF gradient by 7 months of age. This group of patients can be managed safely with relief of BVF obstruction later in infancy.

Single ventricle with systemic obstruction in early life: comparison of initial pulmonary artery banding versus the Norwood operation

OBJECTIVES

The outcomes of initial pulmonary artery banding (PAB)+/-coarctation repair are compared with the Norwood operation in newborns with single ventricle (SV) and systemic obstruction (SO).

METHODS

Between January 1987 and July 2000, 22 patients (median age, 12 days) with SV and aortic arch obstruction (AAO), subaortic stenosis (SAS), or both underwent surgery. Two initial surgical approaches were used: PAB+/-coarctation repair (group I, seven patients); Norwood type operation (group II, 15 patients).

RESULTS

The overall mortality was 32% (seven of 22 patients). There was no late mortality. The mortality in group I was 43% versus 27% in group II. Recently, there has been no mortality following the Norwood operation in the last eight patients operated since 1995. Of the survivors, nine patients have undergone the Fontan operation and four patients have had the bidirectional Glenn (BDG) with no deaths. There was one repair of supravalvar aortic stenosis at the time of BDG in group II as opposed to eight reinterventions for SAS and/or AAO in four patients in group I (P=0.01).

CONCLUSIONS

PAB+/-coarctation repair for SV and SO is associated with a high mortality and a high reoperation rate for SAS or recurrent AAO. Although the Norwood operation was also associated with a high mortality early on, it can now be performed with excellent outcome. This improvement, combined with a low reintervention rate for SAS or AAO, suggests that the Norwood operation is likely to emerge as the procedure of choice for SV and SO.

Transthoracic 3-dimensional echocardiography in the assessment of subaortic stenosis due to a restrictive ventricular septal defect in double inlet left ventricle with discordant ventriculoarterial connections

To evaluate the accuracy and clinical utility of three-dimensional echocardiography in the assessment of the size and shape of the ventricular septal defect in double inlet left ventricle.

METHODS

We validated the technique in an autopsy study, and then performed a clinical investigation. Six autopsied hearts were immersed in a waterbath and examined with 3-dimensional echocardiography. We identified the cross-section within the dataset which optimally displayed the ventricular septal defect "en face", and compared its smallest and largest diameters, as well as its area. The ventricular septal defect was then filled with a silicone sealant and a section prepared for direct measurement. In patients, we measured the diameters and area of the ventricular septal defect in endsystole nad computed the aortic valvar area in endsystole from the cross-section showing the aortic valve "en face". Ten patients with double inlet left ventricle, aged between 2 and 15 years, were studied using rotational or parallel scanning. All patients had undergone banding of the pulmonary trunk at a mean age of 7 (3-36) days, usually at the time of repair of the coarctation. Two patients had undergone surgical enlargement of the ventricular septal defect prior to echocardiographic examination.

RESULTS

The correlation between the areas of the ventricular septal defect in the specimens measured directly and by 3-dimensional echocardiography was r=0.98, with limits of agreement between -0.1-0.08 cm2. In the patients, the area of the defect was measured as 3.9+/-2 cm2, whereas the aortic valvar area was 2.6+/-0.9 cm2. The ratio between the areas was 1.5 (0.5-2.3). Three patients with areas of the ventricular septal defect smaller than those of the aortic valve had resting Doppler gradients between double inlet left ventricle and the aorta of 16, 20 and 30 mm Hgs, respectively.

CONCLUSIONS

3-dimensional echocardiography provides accurate assessment of the area of the ventricular septal defect in double inlet left ventricle, and is helpful in identifying patients with subaortic stenosis caused by restrictive defects.

Does banding the pulmonary artery affect pulmonary valve function after the Damus-Kaye-Stansel operation?

BACKGROUND

The Damus-Kaye-Stansel (DKS) operation can be an effective palliation in patients who have single-ventricle physiology and systemic outflow obstruction. Pulmonary artery banding (PAB) may be used as a preliminary procedure in these patients to limit overperfusion of the pulmonary circulation. In some series, the DKS operation has been associated with pulmonary insufficiency (PI). We retrospectively analyzed medical records of our patients who had PAB and later DKS to determine the incidence of PI in these patients.

METHODS

Between 1982 and 1996, 15 patients underwent PAB before DKS. Median age at PAB placement was 7 days and median duration of PAB was 7 months. Echocardiograms obtained before PAB, before DKS, and at the most recent post-DKS follow-up were reviewed.

RESULTS

Follow-up ranged from 1 to 15 years (mean follow-up, 7.5 years). One patient had trivial PI before PAB, which progressed to moderate PI at the last follow-up. Only 1 other patient had mild PI, but only at the last follow-up after DKS.

CONCLUSIONS

These findings suggest that prior PAB does not appear to cause significant PI in patients slated for DKS, and the incidence of significant PI after the DKS operation is relatively low.

Subaortic obstruction and the Fontan operation

Systemic outflow tract obstruction in the heart with a functional single ventricle promotes myocardial hypertrophy, and this has been shown to be an unequivocal risk factor for poor outcome at Fontan procedure. Such systemic outflow tract obstruction may be congenital or acquired. Those factors contributing to acquired systemic outflow tract obstruction in those patients with a double-inlet left ventricle, a rudimentary right ventricle, and a discordant ventriculoarterial connection include the size of the ventricular septal defect, previous pulmonary artery banding, and other volume unloading surgical procedures. Staging with a bidirectional cavopulmonary connection and construction of a proximal pulmonary artery-aortic connection or ventricular septal defect enlargement has neutralized this factor.

The physiology of the bidirectional cavopulmonary connection

This article reviews the indications for the bidirectional cavopulmonary connection and demonstrates its efficacy in reducing mortality for the Fontan procedure. The indications for adding an additional source of pulmonary blood flow to the bidirectional cavopulmonary connection are discussed, but this issue remains controversial. Also unclear is whether the bidirectional cavopulmonary connection promotes symmetric growth of the pulmonary arteries, or whether growth of the left pulmonary artery is disadvantaged. Finally, systemic venous collateralization is a well-recognized sequel after cavopulmonary connection. The clinical implications of this collateralization are reviewed.

Surgical management of tricuspid atresia and anomalous left brachiocephalic vein

An anomalous left brachiocephalic vein is an uncommon systemic venous anomaly, which usually has no clinical significance. We describe a case of tricuspid atresia with such an anomalous left brachiocephalic vein. The presence of this unusual venous anomaly had a number of implications in the surgical management of the tricuspid atresia.

Acute changes in preload, afterload, and systolic function after superior cavopulmonary connection

BACKGROUND

Superior cavopulmonary connection reduces the volume work of the single ventricle.

METHODS

To determine the effects of superior cavopulmonary connection on preload, wall stress (or afterload), and systolic ventricular function, we studied 9 patients before and after operation, and at hospital discharge. Using echocardiography, preload was estimated by the ventricular end-diastolic area, and wall stress was calculated at end-systole and peak-systole. Ventricular function was represented by rate-corrected velocity of circumferential fiber shortening and fractional area change divided by rate-corrected ejection time.

RESULTS

End-diastolic area and wall stress decreased postoperatively. Ventricular wall thickness increased with a concomitant decrease in cavity area. There was no change in mean blood pressure or heart rate or in rate-corrected velocity of circumferential fiber shortening or fractional area change divided by rate-corrected ejection time. These findings persisted at hospital discharge.

CONCLUSIONS

In single ventricles, superior cavopulmonary correction results in an immediate decrease in preload and afterload. The decrease in afterload results primarily from alterations in ventricular geometry. Although no improvement in systolic function was noted, diminished work related to the reduction in loading conditions may have beneficial long-term effects on preserving myocardial performance.

Modified Damus-Kaye-Stansel procedure for single ventricle, subaortic stenosis, and arch obstruction in neonates and infants: midterm results and techniques for avoiding circulatory arrest

BACKGROUND

A modified Damus-Kaye-Stansel procedure is one of several options for palliation of single ventricle with subaortic obstruction, but results in neonates have been disappointing. In the presence of arch obstruction, this procedure is typically performed with circulatory arrest, which may contribute to neurologic insult.

METHODS

Since 1990, a modified Damus-Kaye-Stansel procedure has been performed in 14 neonates and seven infants with single ventricle and subaortic stenosis, including 15 with arch obstruction. Diagnoses were double-inlet left ventricle (n = 12), tricuspid atresia (n = 2), and other forms of hypoplastic ventricle with subaortic obstruction (n = 7). Three patients underwent concurrent bidirectional Glenn shunt. In the most recent seven patients with arch obstruction, arch repair was achieved with an end-to-side anastomosis of the descending aorta to the ascending aorta with continuous upper body perfusion.

RESULTS

One early death occurred among the 14 neonates (7%) and three among the infants, for an early mortality of 19%. At a median follow-up of 33 months, there were no late deaths or neurologic complications. Nine patients underwent subsequent bidirectional Glenn anastomosis, including three who had Fontan completion and one who later underwent conversion to a partial biventricular repair. One patient required a transplant for cardiomyopathy of unknown etiology. The remaining 12 patients are considered good candidates for Fontan completion. No patient has recurrent arch obstruction. Four patients have mild (n = 1) or trivial (n = 3) semilunar valvular regurgitation.

CONCLUSION

The modified Damus-Kaye-Stansel procedure is an effective primary palliation for single ventricle and subaortic stenosis, with or without arch obstruction. Results are especially encouraging in neonates. Arch repair can be achieved without circulatory arrest to the brain.

Modified Norwood operation for single left ventricle and ventriculoarterial discordance: an improved surgical technique

BACKGROUND

Patients with univentricular hearts and ventriculoarterial discordance with potentially obstructed systemic blood flow continue to pose difficult management problems. The goals of neonatal palliative operations are to control pulmonary blood flow while avoiding pulmonary artery distortion, to relieve systemic outflow tract obstruction, and to avoid heart block.

METHODS

Between January 1987 and December 1996, 38 patients with either tricuspid atresia or a double-inlet left ventricle and ventriculoarterial discordance underwent a modified Norwood procedure. Their mean age was 15 days, and their mean weight was 3.4 kg. Aortic arch anomalies were present in 92% of the patients. Morbidity and mortality statistics, intraoperative data, and postoperative echocardiograms were reviewed.

RESULTS

There were 3 early deaths (7.8%) and 5 late deaths (13.1%). The actuarial survival rates at 1 month, 1 year, and 5 years were 89%, 82%, and 71%, respectively. Follow-up was complete in all children at a mean interval of 30 +/- 9 months. None of the patients had significant neoaortic valve insufficiency, and 1 patient required therapy for residual aortic arch obstruction. Nine patients (30% of the survivors) have undergone the hemi-Fontan procedure, and 18 patients (60%) successfully have undergone the Fontan procedure.

CONCLUSIONS

In this patient population, we recommend the modified Norwood procedure as the neonatal palliative treatment of choice. It can be performed with acceptable early morbidity and mortality, and it improves suitability for the Fontan procedure. It reliably relieves all levels of systemic outflow tract obstruction, controls pulmonary blood flow, and avoids heart block.

Instantaneous Subaortic Obstruction after Closure of Aortopulmonary Shunt

We report the case of a young child with tricuspid atresia, discordant ventriculoarterial connection, rudimentary right ventricle, and mildly restrictive bulboventricular foramen. Intraoperative temporary snaring of the modified Blalock-Taussig shunt resulted in a dramatic volume reduction of the left ventricle, a decrease in bulboventricular foramen size, and an instantaneous increase in the gradient across the latter from 15 mm Hg before occlusion of the shunt to 44 mm Hg. A modified Damus-Stancel-Kaye procedure resulted in early relief of the aortic outflow obstruction; in addition, a bidirectional cavopulmonary anastomosis was constructed. The use of intraoperative echocardiography is recommended to monitor subaortic obstruction in procedures that unload volume in univentricular hearts with discordant ventriculoarterial connection.