Impact of the evolution of the Fontan operation on early and late mortality: a single-center experience of 405 patients over 3 decades

Long-term outcomes of tricuspid valve intervention during stage 2 palliation in patients with a single right ventricle

OBJECTIVES

In patients with single ventricle physiology and a systemic right ventricle, tricuspid valve regurgitation increases the risk of adverse outcomes, and tricuspid valve intervention at the time of staged palliation further increases that risk in the postoperative period. However, long-term outcomes of valve intervention in patients with significant regurgitation during stage 2 palliation have not been established. The purpose of this study is to evaluate the long-term outcomes after tricuspid valve intervention during stage 2 palliation in patients with right ventricular dominant circulation in a multicenter study.

METHODS

The study was performed using the Single Ventricle Reconstruction Trial and Single Ventricle Reconstruction Follow-up 2 Trial datasets. Survival analysis was performed to describe the association among valve regurgitation, intervention, and long-term survival. Cox proportional hazards modeling was used to estimate the longitudinal association of tricuspid intervention and transplant-free survival.

RESULTS

Patients with tricuspid regurgitation at stage 1 or 2 had worse transplant-free survival (hazard ratio, 1.61; 95% confidence interval, 1.12-2.32; hazard ratio, 2.3; 95% confidence interval 1.39-3.82). Those with regurgitation who underwent concomitant valve intervention at stage 2 were significantly more likely to die or undergo heart transplantation compared with those with regurgitation who did not (hazard ratio, 2.93; confidence interval, 2.16-3.99). Patients with tricuspid regurgitation at the time of the Fontan had favorable outcomes regardless of valve intervention.

CONCLUSIONS

The risks associated with tricuspid regurgitation in patients with single ventricle physiology do not appear to be mitigated by valve intervention at the time of stage 2 palliation. Patients who underwent valve intervention for tricuspid regurgitation at stage 2 had significantly worse survival compared with patients with tricuspid regurgitation who did not.

Impact of pulmonary artery flow distribution on Fontan hemodynamics and flow energetics

BACKGROUND

With improved life expectancy following Fontan palliation, there is an increasing population of patients with a total cavopulmonary connection. However, there is a poor understanding of which patients will experience Fontan failure and when. 4D flow MRI has identified several metrics of clinical interest, but longitudinal studies investigating hemodynamics in Fontan patients are lacking.

OBJECTIVE

We aimed to investigate the relationship between flow distribution to the pulmonary arteries and regional hemodynamic metrics in a unique cohort with follow-up 4D flow MRI.

MATERIALS AND METHODS

Patients with > 6 months of 4D flow MRI follow-up were included. Flow distribution from the caval veins to pulmonary arteries was measured in addition to regional measures of peak velocity, viscous energy loss (EL_mean and EL_tot), and kinetic energy.

RESULTS

Ten patients with total cavopulmonary connection (17.7 ± 8.8 years at baseline, follow-up: 4.4 ± 2.6 years) were included. Five subjects had unequal flow distribution from the IVC to the pulmonary arteries at baseline. Over time, these subjects tended to have larger increases in peak velocity (39.2% vs 6.6%), EL_mean (11.6% vs -38.3%), EL_tot (9.5% vs -36.2%), and kinetic energy (96.1% vs 36.3%) in the IVC. However, these differences were statistically insignificant. We found that changes in EL_mean and EL_tot were significantly associated with changes in peak velocity in the caval veins (R² > 0.5, P < 0.001).

CONCLUSION

Unequal flow distribution from the IVC may drive increasing peak velocities and viscous energy losses, which have been associated with worse clinical outcomes. Changes in peak velocity may serve as a surrogate measure for changes in viscous energy loss.

Predictive factors contributing to prolonged recovery in patients after Fontan operation

Background

Prolonged recovery is a severe issue in patients after Fontan operation. However, predictive factors related to this issue are not adequately evaluated. The present study aimed to investigate potential predictive factors which can predict Fontan postoperative recovery.

Methods

We retrospectively reviewed the perioperative medical records of patients with Fontan surgery between January 2015 and December 2018, and divided patients with > 75%ile cardiac intensive care unit stay into prolonged recovery group. The others were assigned to standard recovery group. Patients that died or underwent a Fontan takedown were excluded. Statistical analysis was performed to compare data difference of the two groups.

Results

282/307 cases fulfilled the inclusion criteria. Seventy patients were considered in prolonged recovery and 212 patients were defined as standard recovery. Pre- and intra-operative data showed a higher incidence of heterotaxy syndrome, longer cardiopulmonary bypass and aortic cross-clamp time in the prolonged recovery group. Postoperative information analysis displayed that ventilation time, oxygen index after extubation, hemodynamic data, inotropic score (IS), drainage volume, volume resuscitation, pulmonary hypertension (PH) treatment, and surgical reintervention were significantly different between the two groups. Higher IS postoperatively, and PH treatment and higher fluid resuscitation within two days were independent predictive factors for prolonged recovery in our multivariate model. C-statistic model showed a high predictive ability in prolonged recovery by using the three factors.

Conclusions

Ventilation time, higher IS in postoperative day, and PH treatment and higher fluid resuscitation within two days were independent risk factors and have a high predictability for Fontan prolonged recovery.

Fontan Circulation Associated Organ Abnormalities Beyond the Heart, Lungs, Liver, and Gut: A Systematic Review

Introduction

Patients with a Fontan circulation are at risk for sequelae of Fontan physiology during follow-up. Fontan physiology affects all organ systems and an overview of end-organ damage is needed.

Methods

We performed a systematic review of abnormalities in multiple organ systems for patients with a longstanding Fontan circulation. We searched online databases for articles describing abnormalities in multiple organ systems. Cardio-pulmonary abnormalities, protein losing enteropathy, and Fontan associated liver disease have already extensively been described and were excluded from this systematic review.

Results

Our search returned 5,704 unique articles. After screening, we found 111 articles relating to multiple organ systems. We found abnormalities in, among others, the nervous system, pituitary, kidneys, and musculoskeletal system. Pituitary edema—relating to the unique pituitary vasculature- may affect the thyroid axis. Renal dysfunction is common. Creatinine based renal function estimates may be inappropriate due to myopenia. Both lean muscle mass and bone mineral density are decreased. These abnormalities in multiple organ systems may be related to Fontan physiology, cyanosis, iatrogenic factors, or lifestyle.

Conclusions

Health care providers should be vigilant for hypothyroidism, visual or hearing deficits, and sleep disordered breathing in Fontan patients. We recommend including cystatin C for assessment of renal function. This review may aid health care providers and guide future research.

Systematic Review Registration:https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021232461, PROSPERO, identifier: CRD42021232461.

Intrapulmonary artery septation for pulmonary artery growth in functionally univentricular hearts

The pulmonary artery anatomy is one of the important determinants of Fontan completion and its outcomes in patients with functionally univentricular hearts. Despite several modifications to Fontan operation, unbalanced pulmonary arteries pose a significant challenge in this subset of patients. Intrapulmonary artery septation is a technique, developed to rehabilitate the unilateral hypoplastic pulmonary artery following various initial palliative procedures in functionally univentricular hearts. Literature is sparse on this technique. This article reviews the basic concepts and literature on intrapulmonary artery septation. We also describe our experience with modified intrapulmonary artery septation.

Long-term results of concomitant atrioventricular valve intervention and the Fontan operation

OBJECTIVES

The optimal timing for atrioventricular valve (AVV) repair in patients with a Fontan circulation remains controversial. Few studies have reported the long-term outcomes of AVV repair concomitant with a Fontan operation.

METHODS

From January 2006 to December 2018, a total of 89 patients who developed moderate or severe AVV regurgitation before a Fontan operation were divided into 2 groups: group 1, including 37 patients who did not undergo concomitant AVV repair; and group 2, including 52 patients who received AVV repair concomitant with a Fontan operation.

RESULTS

The mean age at the time of the Fontan operation was 6.74 years for group 1 and 8.96 years for group 2, respectively. Early death occurred in 3 patients [2 patients (5.4%) in group 2, patient 1 (1.9%) in group 1]. Freedom from long-term death, cardiac function reduction and protein-losing enteropathy were similar among the 2 groups. Common AVV function was apparently poorer than mitral valve function after repair [hazard ratio (HR) 3.83, 95% confidence interval (CI) 1.31-11.17; P = 0.014]. The occurrence of AVV valve failure in group 1 was lower than that in group 2 (HR 0.44, 95% CI 0.22-0.91; P = 0.026). AVV function became worse during the follow-up period than that at discharge in both groups (P = 0.03 in group 1 and P = 0.001 in group 2).

CONCLUSIONS

The long-term results of AVV repair concomitant with a Fontan operation are favourable.

Systemic Artery Vasoconstrictor Therapy in Fontan Patients with High Cardiac Output-Heart Failure: A Single-Center Experience

Failed Fontan Patients with high cardiac output (CO) heart failure (HF) might have vasodilatory syndrome and markedly high mortality rates. The aim of this study was to review the clinical effects of vasoconstrictor therapy (VCT) for failed Fontan hemodynamics. We retrospectively reviewed 10 consecutive patients with Fontan failure (median age, 33 years) and high CO-HF who had received VCT. The hemodynamics were characterized by high central venous pressure (CVP: median, 16 mm Hg), low systolic blood pressure (median, 83 mm Hg), low systemic vascular resistance (median, 8.8 U·m²), high cardiac index (median, 4.6 L/min/m²), and low arterial oxygen saturation (median, 89%). VCT included intravenous noradrenaline infusion for five unstable patients, oral midodrine administration for nine stable patients, and both for four patients. After VCT introduction with a median interval of 1.7 months, the median systolic blood pressure (102 mm Hg, p = 0.004), arterial oxygen saturation (90%, p = 0.03), and systemic vascular resistance (12.1 U·m², p = 0.13) increased without significant changes in CVP or cardiac index. After a median follow-up of 21 months, the number of readmissions per year decreased from 4 (1-11) to 1 (0-9) (p = 0.25), and there were no VCT-related complications; however, five patients (50%) developed hepatic encephalopathy, and six patients (60%) eventually died. VCT was safely introduced and could prevent the rapidly deteriorating Fontan hemodynamics. VCT could be an effective therapeutic strategy for failed Fontan patients with high CO-HF.

Pulse oximetry screening for critical congenital heart defects in Ontario, Canada: a cost-effectiveness analysis

OBJECTIVE

Previously conducted cost-effectiveness analyses of pulse oximetry screening (POS) for critical congenital heart defects (CCHDs) have shown it to be a cost-effective endeavour, but the geographical setting of Ontario in relation to its vast yet sparsely populated regions presents unique challenges. The objective of this study was to estimate the cost-effectiveness of POS for CCHD in Ontario, Canada.

METHODS

A cost-effectiveness analysis, comparing POS to no POS, was conducted from the Ontario healthcare payer perspective using a Markov model. The base case was defined as a well-appearing newborn at 24 h of age. Outcome measures, including quality-adjusted life months (QALMs), lifetime costs, and incremental cost-effectiveness ratios (ICER) [ΔCost/ΔQALMs], were calculated over a lifetime horizon. All outcomes were discounted at 1.5% per year. Cost-effectiveness was assessed using an a priori ICER threshold of CAD$4166.67 per QALM (equivalent to CAD$50,000 per quality-adjusted life year). Deterministic and probabilistic sensitivity analyses were conducted to assess parameter uncertainty.

RESULTS

Implementation of POS is expected to lead to timely diagnosis of 51 CCHD cases annually. The incremental cost of performing POS was estimated to be $27.27 per screened individual, with a gain of 0.02455 QALMs. This yielded an ICER of CAD$1110.79 per QALM, well below the pre-determined threshold. The probabilistic sensitivity analysis estimated a 92.3% chance of routine implementation of POS being cost-effective.

CONCLUSION

Routine implementation of POS for CCHD in Ontario is expected to be cost-effective.

Impact of intrapulmonary-artery septation to pulmonary vein obstruction for two-lung Fontan

OBJECTIVES

Patients with unbalanced pulmonary artery (PA) growth and decreased unilateral pulmonary circulation are considered unsuitable candidates for the Fontan procedure. Following our previous study on the utility of intrapulmonary-artery septation for patients with PA hypoplasia, we investigated its use in patients with pulmonary venous obstruction (PVO).

METHODS

We recruited 42 patients who underwent intrapulmonary-artery septation for unilateral PA hypoplasia and/or PVO between 1998 and 2018 and classified them into no PVO or PVO group. We analysed overall survival, success of the Fontan procedure and data from catheterization and echocardiography. In PVO, we evaluated the functional lung area before the Fontan procedure and the relevance of this parameter to operative outcomes.

RESULTS

The PVO and no-PVO group included 24 and 18 patients, respectively. One patient in the no-PVO and 6 patients in the PVO group died during follow-up; this difference was statistically significant (log-rank P = 0.040). In the no-PVO group, 15 (83%) patients achieved two-lung Fontan circulation. In the PVO group, 12 (50%) patients achieved two-lung Fontan circulation. Multivariate analysis revealed that functional lung area and shunt size [significantly larger in patients with functional lung area ≥50% in affected lung (P = 0.040)] were significant factors for successful two-lung Fontan procedure (P = 0.030).

CONCLUSIONS

Intrapulmonary-artery septation may contribute to increase functional lung area after PVO release to establish two-lung Fontan circulation in patients with PVO who have unbalanced PA growth and/or decreased unilateral pulmonary circulation.

11 Years of the Fontan operation at a single institution: Results from 87 consecutive patients

Fontan procedure is the preferred palliation for patients with single ventricles.

OBJECTIVES

To evaluate early morbidity and mortality after Fontan operation in 87 consecutive patients, between 2007 and 2017.

METHODS

Early survival, duration of intensive care unit (ICU), and hospital stays were the main outcomes evaluated. Potential influencing factors evaluated included preoperative and intraoperative variables.

RESULTS

Fontan procedure was performed at a median age of 4.2 years (range, 17 months-26 years), and a median weight of 15.5 kg (range, 8-72 kg). Extracardiac Fontan was the procedure of choice. The median cardiopulmonary bypass time was 122  minutes (range, 58-550 minutes). The majority had a fenestration (75 out of 87). Postoperatively, the median duration of ICU stay and total hospital stay were (4, 1-76 days) and (16, 1-85 days), respectively. Fontan failure occurred in one patient (1%). Overall early survival was 94%, resulting in a mortality rate of 6%. Univariate analysis showed that heterotaxy (odds ratio [OR], 2.222; confidence interval [CI], 1.345-6.250; P = .003) and decreased ventricular function (OR, 2.207; CI, 1.348-6.061; P = .002) significantly decreased survival. The same analysis failed to identify any statistically significant risk factors for prolonged hospital and ICU stays.

CONCLUSION

Our reported mortality and morbidity rates compared favorably with the reported rates. Therefore, Fontan operation can be performed in a tertiary care center in the United Arab Emirates with favorable early postoperative outcomes.

Surgery of single ventricles in humanitarian practice: surgery for which patients?

OBJECTIVES

To analyse the feasibility and effectiveness in humanitarian practice of surgical management of children with single-ventricle heart condition.

METHODS

Retrospective study of children with a single ventricle, managed by the association Mécénat-Chirurgie Cardiaque since 1996, with long-term follow-up after their return home.

RESULTS

Of the 138 children in our cohort, 119 had one or more surgeries (180 procedures): palliative surgery alone (systemic-pulmonary anastomosis or banding), 41; partial cavo-pulmonary connection, 47; total cavo-pulmonary connection (mean age 8.5 years), 31. Operative mortality is 5.5%. After a mean follow-up of 5.6 years, 18 children (13%) were lost to follow-up. Survival at 10 years is 79% in children receiving surgery (palliative only, 72%; partial cavo-pulmonary connection, 77%; total cavo-pulmonary connection, 97%) versus 29% in children with no surgical intervention. The prognosis is better for tricuspid atresia and double-inlet left ventricle (86 and 83% survival at 10 years) than for double-outlet right ventricle or complete atrio-ventricular canal defect (64 and 68% at 5 years).

CONCLUSION

The surgery of the single ventricle in humanitarian medicine allows a very satisfactory survival after one or more surgeries tending towards a total cavo-pulmonary connection as soon as possible.

The Bilateral Bidirectional Glenn Operation as a Risk Factor Prior to Fontan Completion in Complex Congenital Heart Disease Patients

Introduction:

The Glenn procedure is generally performed as a second-stage palliative procedure toward the completion of Fontan circulation in patients with a functionally univentricular heart. Safe Fontan completion requires normal ventricular function, competent atrioventricular valves, normal pulmonary arteries anatomy, and low pulmonary vascular resistances (PVRs), which is merely an estimation that considers both lungs as a single unit. Clinical observations revealed that patients who previously underwent bilateral bidirectional cavopulmonary anastomosis (b-BCPA) had a stormier postoperative course in respect to other patients with previous unilateral BCPA (u-BCPA) postoperatively after Fontan completion. This retrospective study was designed to compare and analyze the outcomes of patients following Fontan completion with previous u-BCPA versus b-BCPA.

Patients and Methods:

A total of 98 patients were divided into two groups based on the presence or absence of bilateral superior vena cava (SVC). Group 1 included 80 patients with unilateral SVC, and group 2 included 18 patients with bilateral SVC. Univariate and multivariate (SPSS) analyses were performed with regard to mortality and failure. P value of <.05 was considered as significant.

Results:

Prior to the total cavopulmonary anastomosis operation, the G1 and G2 had similar demographic and physiological findings, ages and weights were 4.3 ± 1.72 years and 15.0 ± 3.71 kg in G1 and 4.8 ± 3.21 years and 17.5 ± 9.76 kg in G2. Mean end-diastolic ventricular pressures (in mm Hg) were 10.50 ± 2.86 in G1 and 10.28 ± 3.07 in G2 and the mean PVRs (in Woods units) were 1.66 ± 1.29 in G1 and 1.49 ± 0.82 in G2. The Stormy postoperative course, Fontan failure, and early mortality were all significantly higher in G2 in respect to G1 ( P value <.05). G1 mortality rate was 3.7%, 3 patients of 80, while in G2, the mortality rate was 22%, 4 patients of 18. Late Fontan failure rates were 6% for G1 patients where two patients developed pulmonary hypertension, two patients developed heart failure, and one patient had protein losing enteropathy (PLE), and 22% for the G2 patients of which two patients developed heart failure, one patient had PLE, and one patient had persistent low systemic venous saturation.

Conclusions:

Our results have demonstrated that patients after b-BCPA might have a tendency for worse outcomes upon Fontan completion. The b-BCPA is associated with pulmonary artery bifurcation stenosis and presents multiple sources of pulmonary blood flow where conventional PVR calculation might be imprecise and misleading since it considers the lungs as a single unit. Therefore, b-BCPA engenders correction of the conventional PVR calculation to consider each lung separately. Furthermore, the surgical approach for patients with persistent left SVC and univentricular heart should be modified.

Late outcomes after the Fontan procedure in patients with single ventricle: a meta-analysis

OBJECTIVE

More patients with Fontan physiology are reaching adulthood. The purpose of this meta-analysis was to evaluate the late outcomes of patients palliated with Fontan procedure and to assess the risk factors for mortality.

METHODS

PubMed, Embase and Web of Science were queried to retrieve observational studies of survival in patients following the Fontan procedure with ≥5 years of follow-up. A random-effects model was used to determine pooled survival estimates at 5, 10 and 15 years. Meta-regression was used to assess potential moderators for death.

RESULTS

Nineteen articles with a total of 5859 patients were included. The weighted mean follow-up time was 8.94±2.64 years with overall 8.3% deaths and 1.5% transplants. Pooled survival estimates at 5, 10 and 15 years were 90.7%, 87.2% and 87.5%, respectively; and 88.4%, 85.7% and 84.1%, respectively, for studies that included all three time intervals (n=4). Earliest surgical year included in the study, proportion of atriopulmonary connections versus extracardiac conduit or lateral tunnel, and older age at Fontan were associated with higher rates of death, but ventricular morphology was not. Protein-losing enteropathy, reoperation and pacemaker insertion were reported in 2.1%, 5.6% and 6.8% patients, respectively.

CONCLUSIONS

Survival following the Fontan procedure has improved with time and is influenced by Fontan type and age at the time of Fontan. At a mean follow-up of 8.9 years, there was no significant association between survival and ventricular morphology, not taking into account the mortality prior to Fontan.

Fontan Failure and Death in Contemporary Fontan Circulation: Analysis From the Last Two Decades

BACKGROUND

We sought to evaluate the incidence of Fontan failure or complication and its relation to death in patients having contemporary Fontan strategies over 2 decades.

METHODS

Five hundred patients who underwent Fontan completion (extracardiac, n = 326; lateral tunnel, n = 174) from 1985 to 2012 were reviewed. Patient characteristics, modes of Fontan failure/complication and death, and predictors for Fontan failure/complication and death were analyzed.

RESULTS

There were 23 early deaths (4.6%) and 17 late deaths (3.4%), with no early death since 2000. Survival has improved over time (p < 0.001). Twenty-three of 40 patients who died were identified as Fontan failure before death, including ventricular dysfunction (n = 14), pulmonary vascular dysfunction (n = 4), thromboembolism (n = 2), and arrhythmia (n = 4). Mode of death was circulatory failure (n = 18), multiorgan failure (n = 6), pulmonary failure (n = 3), cerebral/renal (n = 5), and sudden death (n = 4). Modes of failure/complication were directly (65%) or conceivably (10%) related to death in 30 of 40 patients (75%). Forty-eight percent of survivors had late Fontan complication(s). Five-year freedom from late Fontan complication was lower among patients who died compared with patients who survived (29.4% versus 53.3%, p < 0.001). Ventricular dysfunction (p = 0.001) and higher pulmonary artery pressures (p < 0.001) after Fontan were predictors for death. Longer cardiopulmonary bypass time (p = 0.032) and reinterventions (p < 0.001) were predictors for late Fontan complication.

CONCLUSIONS

Early death in the early era has been overcome. Yet the incidence and causes of late death remain unchanged. There was a strong causative relationship between the mode of Fontan failure/complication and death, indicating the importance of early recognition and treatment of Fontan failure/complication.

Externally applied compression therapy for Fontan patients

BACKGROUND

Limited therapeutic options are available for Fontan patients with dysfunctional or failing single ventricle physiology. This study describes the evaluation of an alternative, non-invasive, at-home therapeutic compression treatment for Fontan patients. Our hypothesis is that routinely administered, externally applied compression treatments to the lower extremities will augment systemic venous return, improve ventricular preload, and thus enhance cardiac output in Fontan patients.

METHODS

To initially evaluate this hypothesis, we employed the NormaTec pneumatic compression device (PCD) in a pilot clinical study (n=2). This device is composed of inflatable trouser compartments that facilitate circumferentially and uniformly applied pressure to a patient's lower extremities. Following an initial health screening, test subjects were pre-evaluated with a modified-Bruce treadmill exercise stress test, and baseline data on cardiorespiratory health was collected. After training, test subjects conducted 6 days of external compression therapy at-home. Subjects were then re-evaluated with a final treadmill stress test and data acquisition of new cardiorespiratory parameters.

RESULTS

Both subjects demonstrated improvement in exercise duration time, peak oxygen volume, and ventilator threshold, as compared to the baseline evaluation.

CONCLUSIONS

These findings are promising and provide the foundation for future studies that will focus on increasing study participation (sample size) to better assess the clinical benefit of compression therapy for Fontan patients.

Life After Surviving Fontan Surgery: A Meta-Analysis of the Incidence and Predictors of Late Death

AIM

We now know that 20-40% of patients with a single ventricle will develop heart failure after the second decade post-Fontan surgery. However, we remain unable to risk-stratify the cohort to identify patients at highest risk of late failure and death. We conducted a systematic review of all reported late outcomes for patients with a Fontan circulation to identify predictors of late death.

METHODS

We searched MEDLINE, Embase and PubMed with subject terms ("single ventricle", "Hypoplastic left heart syndrome", "congenital heart defects" or "Fontan procedure") AND ("heart failure", "post-operative complications", "death", "cause of death", "transplantation" or "follow-up studies") for relevant studies between January 1990 and December 2015. Variables identified as significant predictors of late death on multivariate analysis were collated for meta-analysis. Survival data was extrapolated from Kaplan-Meier survival curves to generate a distribution-free summary survival curve.

RESULTS

Thirty-four relevant publications were identified, with a total of 7536 patients included in the analysis. Mean follow-up duration was 114 months (range 24-269 months). There were 688 (11%) late deaths. Predominant causes of death were late Fontan failure (34%), sudden death (19%) and perioperative death (16%). Estimated mean survival at 5, 10 and 20 years post Fontan surgery were 95% (95%CI 93-96), 91% (95%CI 89-93) and 82% (95%CI 77-85). Significant predictors of late death include prolonged pleural effusions post Fontan surgery (HR1.18, 95%CI 1.09-1.29, p<0.001), protein losing enteropathy (HR2.19, 95%CI 1.69-2.84, p<0.001), increased ventricular end diastolic volume (HR1.03 per 10ml/BSA increase, 95%CI 1.02-1.05, p<0.001) and having a permanent pacemaker (HR12.63, 95%CI 6.17-25.86, p<0.001).

CONCLUSIONS

Over 80% of patients who survive Fontan surgery will be alive at 20 years. Developing late sequelae including protein losing enteropathy, ventricular dysfunction or requiring a pacemaker predict a higher risk of late death.

Where Is the "Optimal" Fontan Hemodynamics?

Fontan circulation is generally characterized by high central venous pressure, low cardiac output, and slightly low arterial oxygen saturation, and it is quite different from normal biventricular physiology. Therefore, when a patient with congenital heart disease is selected as a candidate for this type of circulation, the ultimate goals of therapy consist of 2 components. One is a smooth adjustment to the new circulation, and the other is long-term circulatory stabilization after adjustment. When either of these goals is not achieved, the patient is categorized as having "failed" Fontan circulation, and the prognosis is dismal. For the first goal of smooth adjustment, a lot of effort has been made to establish criteria for patient selection and intensive management immediately after the Fontan operation. For the second goal of long-term circulatory stabilization, there is limited evidence of successful strategies for long-term hemodynamic stabilization. Furthermore, there have been no data on optimal hemodynamics in Fontan circulation that could be used as a reference for patient management. Although small clinical trials and case reports are available, the results cannot be generalized to the majority of Fontan survivors. We recently reported the clinical and hemodynamic characteristics of early and late failing Fontan survivors and their association with all-cause mortality. This knowledge could provide insight into the complex Fontan pathophysiology and might help establish a management strategy for long-term hemodynamic stabilization.

Current Therapy for Hypoplastic Left Heart Syndrome and Related Single Ventricle Lesions

Universally fatal only 4 decades ago, the progress in the 3-stage palliation of hypoplastic left heart syndrome and related single right ventricular lesions has drastically improved the outlook for these patients. Although the stage II operation (hemi-Fontan or bidirectional Glenn) and stage III Fontan procedure have evolved into relatively low-risk operations, the stage I Norwood procedure remains one of the highest-risk and costliest common operations performed in congenital heart surgery. Yet, despite this fact, experienced centers now report hospital survivals of >90% for the Norwood procedure. This traditional 3-stage surgical palliation has seen several innovations in the past decade aimed at improving outcomes, particularly for the Norwood procedure. One significant change is a renewed interest in the right ventricle-to-pulmonary artery shunt as the source of pulmonary blood flow, rather than the modified Blalock-Taussig shunt for the Norwood. The multi-institutional Single Ventricle Reconstruction trial randomly assigned 555 patients to one or the other shunt, and these subjects continue to be followed closely as they now approach 10 years postrandomization. In addition to modifications to the Norwood procedure, the hybrid procedure, a combined catheter-based and surgical approach, avoids the Norwood procedure in the newborn period entirely. The initial hybrid procedure is then followed by a comprehensive stage II, which combines components of both the Norwood and the traditional stage II, and later completion of the Fontan. Proponents of this approach hope to improve not only short-term survival, but also potentially longer-term outcomes, such as neurodevelopment, as well. Regardless of the approach, traditional surgical staged palliation or the hybrid procedure, survivals have vastly improved, and large numbers of these patients are surviving not only through their Fontan in early childhood, but also into adolescence and young adulthood. As this population grows, it becomes increasingly important to understand the longer-term outcomes of these Fontan patients, not only in terms of survival, but also in terms of the burden of disease, neurodevelopmental outcomes, psychosocial development, and quality of life.

Heart transplantation for adults with congenital heart disease: current status and future prospects

Increased survival rates after corrective or palliative surgery for complex congenital heart disease (CHD) in infancy and childhood are now being coupled with increased numbers of patients who survive to adulthood with various residual lesions or sequelae. These patients are likely to deteriorate in cardiac function or end-organ function, eventually requiring lifesaving treatment including heart transplantation. Although early and late outcomes of heart transplantation have been improving for adult survivors of CHD, outcomes and pretransplant management could still be improved. Survivors of Fontan procedures are a vulnerable cohort, particularly when single ventricle physiology fails, mostly with protein-losing enteropathy and hepatic dysfunction. Therefore, we reviewed single-institution and larger database analyses of adults who underwent heart transplantation for CHD, to enable risk stratification by identifying the indications and outcomes. As the results, despite relatively high early mortality, long-term results were encouraging after heart transplantation. However, further investigations are needed to improve the indication criteria for complex CHD, especially for failed Fontan. In addition, the current system of status criteria and donor heart allocation system in heart transplantation should be arranged as suitable for adults with complex CHD. Furthermore, there is a strong need to develop ventricular assist devices as a bridge to transplantation or destination therapy, especially where right-sided circulatory support is needed.

Impact of Era, Type of Isomerism, and Ventricular Morphology on Survival in Heterotaxy: Implications for Therapeutic Management

BACKGROUND

Heterotaxy has been demonstrated to reduce survival. There are several different subgroups of patients, however, and no single study has had a large number of patients and analyzed survival across the different subgroups such as patients born in different eras, patients with right and left isomerism, and patients with biventricular or functionally univentricular hearts. This study pools previously reported data from Kaplan-Meier curves and performs such subgroup analysis.

METHODS

A systematic review of the literature was performed to identify studies reporting survival of patients with the so-called "heterotaxy" by means of Kaplan-Meier survival curves. Data were extracted from these survival curves and then pooled together. A polynomial regression was then used to generate a pooled survival curve. This was done for all patients, those born in a more recent era, those with right and left isomerism, and those with biventricular or functionally univentricular hearts.

RESULTS

Those born in the more recent era (after 2000) had increased survival compared to the overall cohort. Those with left isomerism tended to have a survival benefit compared to those with right isomerism until about 16 years of age, beyond which those with right isomerism developed a survival benefit. Those with biventricular hearts had a survival benefit compared to those with left isomerism.

CONCLUSION

Survival in the so-called heterotaxy syndrome is based on several factors, which include era of birth, sidedness of isomerism, and whether the heart is biventricular or functionally univentricular.

[Comparison between patients undergoing Fontan operation with or without cardiopulmonary bypass]

Fontan operation is the final palliative stage of patients with univentricular hearts. Cardiopulmonary bypass (CPB) decreases ventricular performance and increases pulmonary artery pressures in the post operative recovery period. It seems that Fontan operation performed without CPB decreases short term morbidity and intra hospitalary length of stay.

OBJETIVE

Compare outcome in Fontan patients who have undergone surgery with or without CPB.

METHOD

This is a retrospective review of patients undergoing Fontan operation from january 2009 to december 2012. Patients were grouped according to CPB use and comparative analyses were done.

RESULTS

Ten patients were operated without CPB use. There was a discrepancy between age in both groups, being younger in the no CPB group. Around 80% of patients in both groups had a staged procedure. A 18mm graft was used in half of the cases; a fenestration was created in all cases. Length of stay was equal in both groups, there was less need of pharmacologic support and nitric oxide use in patients without CPB use. No deaths were reported also in this group. At folllow up, most patients had a class i functional status.

CONCLUSIONS

In our experience, Fontan operation without CPB has similar outcomes compared with CPB use.

Comparison Between Echocardiography and Cardiac Magnetic Resonance Imaging in Predicting Transplant-Free Survival After the Fontan Operation

Adverse outcomes increase in frequency as patients after Fontan operation approach adulthood. Cardiac magnetic resonance (CMR) imaging-derived parameters have been shown to predict death/transplant; however, limited data are available on the usefulness of echocardiography in risk stratification. We conducted a retrospective, single-center review of records of patients after Fontan operation with an echocardiogram and CMR within 1 year of each other. The primary end point was time to all-cause mortality or listing for transplant. Of the 127 eligible patients, there were 12 end points (9%; 10 deaths and 2 listing for transplant). Median age was 16.8 years (interquartile range 12 to 23.1) with a median follow-up of 3.8 years (interquartile range 2.6 to 5.7). Among clinical parameters, protein-losing enteropathy had the strongest association with the outcome. Among echocardiographic variables, global circumferential strain showed the strongest association (hazard ratio 1.3 per unit change, 95% confidence interval 1.1 to 1.5, p value 0.001, C-index 0.81), whereas among CMR variables indexed ventricular end-diastolic volume showed the strongest association with the outcome (hazard ratio 1.04 per 10 ml/BSA(1.3) increase in volume, 95% confidence interval 1.02 to 1.06, p value 0.001, C-index 0.82). Cox proportional hazards analysis revealed echocardiography and CMR models to each individually have a higher predictive ability than the clinical model; however, in direct comparison, neither technique was superior. In conclusion, both echocardiography-derived circumferential strain and CMR-derived ventricular end-diastolic volume index are associated with transplant-free survival in patients after Fontan operation. Echocardiography and CMR parameters have higher discriminative ability than clinical variables. Although neither imaging technique is superior in this cohort, both introduce important factors for risk stratification.

Biomarkers in pediatric heart disease

A biomarker is a characteristic that can be used as an indicator of a biological state. A biomarker can be a clinical observation, laboratory test or an imaging parameter. In this review, we discuss the use of biomarkers in differentiating cardiac from noncardiac disease; predicting the prognosis of patients with heart failure, pulmonary hypertension and dilated cardiomyopathy; diagnosing subclinical cardiac involvement in muscular dystrophy and postchemotherapy cancer patients; detecting acute rejection following heart transplantation; diagnosing Kawasaki disease; aiding the management of postoperative cardiac patients; and managing both common (tetralogy of Fallot) and complex (single-ventricle physiology) congenital heart diseases.

Patient-specific assessment of cardiovascular function by combination of clinical data and computational model with applications to patients undergoing Fontan operation

The assessment of cardiovascular function is becoming increasingly important for the care of patients with single-ventricle defects. However, most measurement methods available in the clinical setting cannot provide a separate measure of cardiac function and loading conditions. In the present study, a numerical method has been proposed to compensate for the limitations of clinical measurements. The main idea was to estimate the parameters of a cardiovascular model by fitting model simulations to patient-specific clinical data via parameter optimization. Several strategies have been taken to establish a well-posed parameter optimization problem, including clinical data-matched model development, parameter selection based on an extensive sensitivity analysis, and proper choice of parameter optimization algorithm. The numerical experiments confirmed the ability of the proposed parameter optimization method to uniquely determine the model parameters given an arbitrary set of clinical data. The method was further tested in four patients undergoing the Fontan operation. Obtained results revealed a prevalence of ventricular abnormalities in the patient cohort and at the same time demonstrated the presence of marked inter-patient differences and preoperative to postoperative changes in cardiovascular function. Because the method allows a quick assessment and makes use of clinical data available in clinical practice, its clinical application is promising.

Outcomes of the Extracardiac Fontan Procedure Using Cardiopulmonary Bypass: Early Results

<p><strong>Background</strong>: Although the avoidance of cardiopulmonary bypass during the Fontan procedure has potential advantages, using cardiopulmonary bypass during this procedure has no adverse effects in terms of morbidity and mortality rates. In this study, we assessed the postoperative outcomes of our first 9 patients who have undergone extracardiac Fontan operation by the same surgeon using cardiopulmonary bypass.</p><p><strong>Methods</strong>: Between September 2011 and April 2013,  9 consecutive patients (3 males and 6 females) underwent extra-cardiac Fontan operation. All operations were performed under cardiopulmonary bypass at normothermia by the same surgeon.  The age of patients ranged between 4 and 17 (9.8 ± 4.2) years. Previous operations performed on these patients were modified Blalock-Taussig shunt procedure in 2 patients, bidirectional cavopulmonary shunt operation in 6 patients, and pulmonary arterial banding in 1 patient. Except 2 patients who required intracardiac intervention, cross-clamping was not applied. In all patients, the extracardiac Fontan procedure was carried out by interposing an appropriately sized tube graft between the infe-rior vena cava and right pulmonary artery.</p><p><strong>Results</strong>: The mean intraoperative Fontan pressure and transpulmonary gradient were 12.3 ± 2.5 and 6.9 ± 2.2 mm Hg, respectively. Intraoperative fenestration was not required. There was no mortality and 7 patients were discharged with-out complications. Complications included persistent pleural effusion in 1 patient and a transient neurological event in 1 patient. All patients were weaned off mechanical ventila-tion within 24 hours. The mean arterial oxygen saturation increased from 76.1% ± 5.3% to 93.5% ± 2.2%. All patients were in sinus rhythm postoperatively. Five patients required blood and blood-product transfusions. The mean intensive care unit and hospital stay periods were 2.9 ± 1.7 and 8.2 ±  1.9 days, respectively.</p><p><strong>Conclusions</strong>: The extracardiac Fontan operation per-formed using cardiopulmonary bypass provides satisfactory results in short-term follow-up and is associated with favor-able postoperative hemodynamics and morbidity rates.</p>

Atrial and ventricular mechanics in patients after Fontan-type procedures: atriopulmonary connection versus extracardiac conduit

BACKGROUND

Differences in systemic venous flow dynamics and energy losses exist in various Fontan-type procedures, which may affect atrial and ventricular filling. The aim of this study was to test the hypothesis that atrial and ventricular mechanics differ between two types of Fontan procedures, atriopulmonary connection (APC) and extracardiac conduit, which have distinctly different systemic venous hemodynamics.

METHODS

This was a cross-sectional, case-control study of 28 Fontan patients (13 with APC, 15 with extracardiac conduit) aged 19.8 ± 6.5 years and 26 healthy controls. Atrial and systemic ventricular myocardial deformation was determined using speckle-tracking echocardiography, while ventricular volumes and systolic dyssynchrony index were assessed using three-dimensional echocardiography.

RESULTS

Compared with controls, patients had significantly lower values of global ventricular longitudinal, circumferential, and radial systolic strain in all three directions, reduced systolic and early diastolic strain rates (SRs) in more than one dimension, lower ejection fractions, and worse ventricular dyssynchrony. For atrial deformation, patients had lower global and positive strain and conduit and reservoir SRs and delayed electromechanical coupling. Among patients, those with APC had significantly lower ventricular longitudinal strain and early diastolic SRs, worse ventricular dyssynchrony, and reduced atrial positive and negative strain and conduit and active contractile SRs. Atrial global strain (r = 0.60, P = .001) and conduit SR (r = 0.49, P = .008) correlated positively with systemic ventricular early diastolic SR.

CONCLUSIONS

Atrial and ventricular mechanics are impaired in patients after Fontan-type operation, which is worse with APC than extracardiac conduit.

Comparison of prognostic variables in children and adults with Fontan circulation

BACKGROUND

Non-cardiac complications, such as hepato-renal and metabolic problems, are emerging late after the Fontan operation due to its unique hemodynamics. Consequently, associations between clinical variables and postoperative outcome may change during the prolonged postoperative course.

METHODS AND RESULTS

To determine if child and adult Fontan patients differ in the impact of cardiac and non-cardiac variables on clinical outcome, we prospectively evaluated associations between hemodynamics, neurohumoral factors, exercise variables, hepato-renal function and metabolic variables and unscheduled hospitalization, including death in 167 consecutive child and 116 adult Fontan patients. When compared with child patients, the adult patients showed higher rates of medications, lower cardiac index, higher values of natriuretic peptides, greater renal dysfunction, more cholestatic livers, and more impaired responses to exercise (p<0.05-0.0001). During the follow-up of 3.7 ± 2.1 years, 64 clinical events (37 in adults), including 13 deaths, occurred. A high CVP and low arterial oxygen satutration strongly predicted the child events (p<0.001), whereas these prognostic parameters were marginal in the adults. Instead, renal dysfunction and metabolic abnormality predicted adult events (p<0.05). Neurohumoral activation, low albumin, hyponatremia, and impaired exercise variables equally predicted clinical events in child and adult Fontan patients.

CONCLUSIONS

Distinctive differences in predictive value of clinical variables exist between child and adult Fontan patients. In addition to cardiac issues, we should consider non-cardiac determinents of clinical outcome to maximize our efforts to improve prognosis for adult Fontan survivors.

Reflections on five decades of the fontan kreutzer procedure

The first successful total right heart bypass via atriopulmonary anastomosis (APA) were reported in 1971 for patients with tricuspid atresia. At the Children's Hospital of Buenos Aires, the cohort of such procedures started in July, when the first fenestrated right heart by pass was performed, with the interposition of a homograft between the right atrial appendage and the main pulmonary artery. In the second patient, instead of placing a homograft, the APA was achieved with the patient's own pulmonary root harvested from the outflow tract of the right ventricle. These techniques were soon replaced in 1978 with the development of the direct valveless posterior APA. Since the very beginning the principle was that the right atrium only functions as a pathway rather than a pump (reason why no inferior vena cava valves were ever used), and the diastolic properties of the systemic ventricle regulate the only real "pump" of this system. The late hemodynamic problems inherent of the APA diminished with modern surgical techniques like the lateral tunnel (LT) or the extracardiac conduit (EC). In spite of the improvement in prognosis and quality of life that the modern techniques have brought for univentricular hearts (UH), with the passing of time, deterioration of this system is frequently seen, due to chronic low cardiac output, elevated central venous pressure making heart transplantation the final stage of treatment. Progressive increase in pulmonary vascular resistances and ventricular dysfunction result in a decline in quality of life and survival. However, the timing of this occurrence is variable, and many survivors enjoy today a satisfactory clinical status. The challenge is to develop a better solution for UH, but in the mean time the Fontan Kreutzer palliation represents the best and only surgical option. It is undoubtedly one of the triumphs of cardiac surgery in congenital heart disease.

Long-term outcomes of common atrioventricular valve plasty in patients with functional single ventricle

OBJECTIVES

Common atrioventricular valve (CAVV) regurgitation is widely known as a risk factor for mortality and Fontan completion in patients with functional single ventricle. Hence, we reviewed our surgical experience with CAVV plasty in Fontan candidates.

METHODS

Staged Fontan strategy and extracardiac total cavopulmonary connection as Fontan modification were our principal approaches in 1995. Since then, 38 consecutive Fontan candidates (21 males, median weight at operation was 7.0 kg and median age was 17 months old) underwent CAVV plasty. Right atrial isomerism was associated with 24 patients. The initial CAVV plasty was performed before inter-stage bidirectional Glenn (BDG) in 3 patients, at BDG in 23, before Fontan in 4 and during Fontan in 8. Since 1995, the modified Alfieri technique with a tailed, expanded, polytetrafluoroethylene tube as a bridging strip was the procedure for repair and 27 patients underwent the procedure. The mean follow-up period was 7.1 years (range 0-17 years).

RESULTS

Actuarial survival and freedom from CAVV replacement rates at 1, 5 and 10 years were 81, 70 and 67% and 89, 85 and 75%, respectively. Seven patients ultimately underwent CAVV replacement with one death. Twenty-three of the 38 patients completed Fontan operation (61%). Association with total anomalous pulmonary venous connection (P= 0.01) and CAVV plasty before BDG (P= 0.05) were risk factors for mortality.

CONCLUSIONS

CAVV plasty for patients with functional single ventricle is still challenging; however, the aggressive and repeated surgical intervention may contribute to provide better life-prognosis. The ventricular volume unloading effect of BDG without additional pulmonary blood flow or Fontan operation did not contribute to maintain CAVV function. Therefore, there would not be any hesitation for CAVV replacement to control CAVVR in the setting of systemic ventricular failure. Although the statistically significant therapeutic superiority of the modified Alfieri technique was not shown so far, further follow-up may reveal the advantage of this easy and simple technique.

Transient hemodynamic changes upon changing a BCPA into a TCPC in staged Fontan operation: a computational model study

The clinical benefits of the Fontan operation in treating single-ventricle defects have been well documented. However, perioperative mortality or morbidity remains a critical problem. The purpose of the present study was to identify the cardiovascular factors that dominate the transient hemodynamic changes upon the change of a bidirectional cavopulmonary (Glenn) anastomosis (BCPA) into a total cavopulmonary connection (TCPC). For this purpose, two computational models were constructed to represent, respectively, a single-ventricle circulation with a BCPA and that with a TCPC. A series of model-based simulations were carried out to quantify the perioperative hemodynamic changes under various cardiovascular conditions. Obtained results indicated that the presence of a low pulmonary vascular resistance and/or a low lower-body vascular resistance is beneficial to the increase in transpulmonary flow upon the BCPA to TCPC change. Moreover, it was found that ventricular diastolic dysfunction and mitral valve regurgitation, despite being well-known risk factors for poor postoperative outcomes, do not cause a considerable perioperative reduction in transpulmonary flow. The findings may help physicians to assess the perioperative risk of the TCPC surgery based on preoperative measurement of cardiovascular function.

High incidence of Dacron conduit stenosis for extracardiac Fontan procedure

OBJECTIVES

Extracardiac conduits are widely used to complete a Fontan circulation in patients with univentricular hearts. Although polytetrafluoroethylene conduits have proven good long-term patency, Dacron (polyethylene terephthalate) prostheses are still infrequently applied, with, as yet, no information on the long-term patency.

METHODS

All patients who received an extracardiac Dacron conduit (n = 12) were retrospectively studied. The initial conduit size was 16 mm in all recipients. The mean age at Fontan completion was 3.1 ± 0.7 years. Patients with clinical symptoms and/or significant conduit stenosis (>50% of diameter) underwent reoperation.

RESULTS

Of the 12 patients, 8 underwent reoperation (75%) at a mean interval of 6.5 ± 1.8 years after the Fontan operation. All conduits were replaced by an 18-mm polytetrafluoroethylene graft. The explants showed ubiquitous tissue deposits on the inner surface, with a residual internal diameter from 8 to 11 mm. All patients survived the extracardiac conduit replacement. Recovery was uneventful, except that 1 patient experienced long-lasting pleural fluid drainage. The mean hospital stay was 10.6 ± 12.0 days.

CONCLUSIONS

The incidence of extracardiac Dacron conduit stenosis in total cavopulmonary connection patients is high. These data indicate that the use of this type of conduit should be avoided. Vigilant follow-up is advised for those patients who have undergone Fontan completion with a Dacron extracardiac conduit.

End-of-life care in adults with congenital heart disease: now is the time to act

PURPOSE OF REVIEW

There are increasing numbers of adults with congenital heart disease (CHD) and these patients remain at long-term risk of complications and premature death. This review focuses on the changing picture of adult CHD with more complex patients surviving, the challenges of balancing life-prolonging intervention, the barriers to discussing the end-of-life (EOL) issues and draws on the experience of other specialities in managing young patients.

RECENT FINDINGS

The prevalence of adults with the most severe forms of CHD has increased, especially those with a Fontan circulation. The eventual decline is inevitable with limited treatment options. There should be a parallel palliative care approach in patients who are being considered for high-risk, life-prolonging interventions. Oncologists caring for the young patients with cancer and cystic fibrosis specialists have demonstrated the unique needs of young patients with chronic diseases that may be applicable to adult CHD patients and help with their EOL planning.

SUMMARY

These patients require an early and proactive approach to EOL discussions, and the unique needs of young patients should be recognized. Further research is needed to develop local and national guidelines for the palliative care approach in these patients.

Extracardiac conduit Fontan procedure versus intra-atrial lateral tunnel Fontan procedure

The Fontan procedure has provided excellent surgical palliation for patients with various types of univentricular hearts, and it has evolved over time. Among many modifications, the lateral tunnel Fontan connection (LTF) and the extracardiac Fontan connection (ECF) are currently the most popular techniques for completing the total cavopulmonary connection. The advantages and disadvantages of both techniques are reviewed here. The advantages of the ECF includes adaptability to all types of univentricular hearts, ease of construction without aortic cross clamping and fewer atrial suture lines. The advantages of the LTF include the ability to complete Fontan circulation in young, very small patients with potential for growth. This review also compares post-operative arrhythmias and fluid dynamics associated with both techniques.

Tissue-engineered vascular grafts for use in the treatment of congenital heart disease: from the bench to the clinic and back again

Since the first tissue-engineered vascular graft (TEVG) was implanted in a child over a decade ago, growth in the field of vascular tissue engineering has been driven by clinical demand for improved vascular prostheses with performance and durability similar to an autologous blood vessel. Great strides were made in pediatric congenital heart surgery using the classical tissue engineering paradigm, and cell seeding of scaffolds in vitro remained the cornerstone of neotissue formation. Our second-generation bone marrow cell-seeded TEVG diverged from tissue engineering dogma with a design that induces the recipient to regenerate vascular tissue in situ. New insights suggest that neovessel development is guided by cell signals derived from both seeded cells and host inflammatory cells that infiltrate the graft. The identification of these signals and the regulatory interactions that influence cell migration, phenotype and extracellular matrix deposition during TEVG remodeling are yielding a next-generation TEVG engineered to guide neotissue regeneration without the use of seeded cells. These developments represent steady progress towards our goal of an off-the-shelf tissue-engineered vascular conduit for pediatric congenital heart surgery.