Relationship of Ventricular Morphology and Atrioventricular Valve Function to Long-Term Outcomes Following Fontan Procedures.

BACKGROUND: The influence of ventricular morphology on Fontan outcomes is controversial. OBJECTIVES: This study hypothesized that dysfunction of the single right ventricle (RV) and right atrioventricular valve regurgitation (AVVR) increases over time and adversely impacts late outcomes following a Fontan operation. A single-center retrospective study was performed. METHODS: From 1985 through 2018, 1,162 patients underwent the Fontan procedure at our center and were included in this study. Transplant and takedown free survival, ventricular, and atrioventricular valve dysfunction after Fontan were analyzed. Death or heart transplantation information was obtained from the National Death Index and the Scientific Registry of Transplant Recipients. RESULTS: The follow-up rate was 99%. Morphologic RV was present in 58% of patients. Transplant and takedown free survival were 91%, 75%, and 71% at 10 years, 20 years, and 25 years, respectively. Morphologic RV was an independent risk factor for transplant, takedown free survival (hazard ratio: 2.4; p = 0.008). The AVVR, which preceded ventricular dysfunction in most cases, was associated with the development of ventricular dysfunction after Fontan (odds ratio: 4.3; 95% confidence interval: 2.7 to 6.7; p < 0.001). Furthermore, AVVR and ventricular dysfunction progressed over time after Fontan, especially in the RV (AVVR: p < 0.0001, ventricular dysfunction: p < 0.0001). CONCLUSIONS: Morphologic RV is negatively associated with the long-term survival following the Fontan, possibly due to a tendency toward progressive AVVR and deterioration of the single ventricle function. Additional volume overload caused by AVVR may be one of the main factors accelerating the dysfunction of the single RV, implying that early valve intervention may be warranted.

Mechanical Circulatory Support for the Failing Fontan: Conversion to Assisted Single Ventricle Circulation-Preliminary Observations.

BACKGROUND: Mechanical circulatory support (MCS) of a failing Fontan circulation remains challenging. We hypothesized that MCS can be provided by converting the Fontan circulation into a mechanically assisted single ventricle parallel circulation (MASVC). METHODS: A porcine model of functionally univentricular circulation was created under cardiopulmonary bypass (CPB) by performing an atrial septectomy, tricuspid valvectomy, and interrupting antegrade pulmonary blood flow. A centrifugal flow pump was placed with inflow from the common atrium. Eight millimeter Dacron grafts anastomosed to the ascending aorta and main pulmonary artery supplied systemic (Qs) and pulmonary (Qp) blood flow. Ultrasonic flow probes were used to measure Qs and Qp after weaning from CPB. The Qp/Qs ratio was regulated using an adjustable clamp. Hemodynamic and laboratory data were recorded. RESULTS: All four animals were successfully weaned from CPB onto the MASVC for a duration of two hours. Mechanically assisted single ventricle parallel circulation achieved satisfactory hemodynamics. As anticipated, the arterial oxygen saturation and partial pressure of oxygen in arterial blood were lower in the MASVC compared to baseline biventricular circulation. At the conclusion of the study, there was a trend towards a decrease in the mixed venous saturation with increasing oxygen extraction compared to the baseline. Serum lactate levels increased after weaning from CPB and did not return to baseline after two hours of support. CONCLUSION: Mechanically assisted single ventricle parallel circulation can be established in a single ventricle animal model. This strategy could potentially provide MCS of a single ventricle circulation. Studies with longer duration of support are required to assess adequacy of support and long-term sustainability.

Follow-Up of a Prospective Surgical Strategy to Prevent Intra-Atrial Reentrant Tachycardia After the Fontan Operation.

BACKGROUND: Intra-atrial reentrant tachycardia (IART) after the Fontan operation had an early reported incidence of 10% to 35% during early and intermediate follow-up and posed substantial management challenges. METHODS AND RESULTS: To reduce the incidence of IART after the Fontan procedure, we performed a randomized, double-blind study to evaluate the impact of an incision in the right atrium joining the lateral tunnel suture line and the tricuspid valve annulus. Between March 1998 and September 2003, 134 subjects (median age: 1.8 years; range: 1.3-5.2 years; 91 men) were randomly assigned to receive the incision. All 134 patients had a form of single ventricle pathological anatomy. The clinical course, electrocardiograms, and Holter monitoring were available for review in 114 subjects at a median of 8.2-year follow-up (range: 0.9-11.9 years). There were 2 late deaths, neither subject had IART. The combined incidence of sustained IART was 3.5% (4/114). There was no difference in the occurrence of sustained IART between those subjects receiving the incision and those who did not (2 in each group) during follow-up. No patients of either group experienced short-term complications. CONCLUSIONS: Despite the fact that the primary outcome of this trial was not reached, the most significant finding was that with current management, the incidence of IART is considerably lower than the early retrospective, observational studies suggested.

Long-Term Survival and Freedom From Reoperation After Placement of a Pulmonary Xenograft Valved Conduit.

BACKGROUND: The optimal choice for pulmonary valve replacement (PVR) remains controversial. This study hypothesized that xenografts used for PVR would result in prolonged long-term survival and freedom from reoperation. METHODS: Children and adults with congenital heart disease requiring PVR using a xenograft from 1980 to 1985 were reviewed. In all cases, the xenograft valve was either sewn or manufactured into a Dacron conduit, and the conduit was sewn to the pulmonary artery bifurcation. Clinical data were analyzed, and survival and freedom from reoperation were determined using Kaplan-Meier analysis. RESULTS: Twenty-four patients received a xenograft for PVR at 14.6 ± 5.6 years. Conduit size ranged from 21 to 27 mm. Most patients received a Carpentier-Edwards valved conduit (n = 17), followed by a Hancock valved conduit (n = 5) and an Ionescu-Shiley valve sewn into a Dacron graft (n = 2). No perioperative deaths occurred. Reoperation was required mainly for pulmonary stenosis (72.7%), followed by pulmonary insufficiency (18.2%), or both stenosis and insufficiency (9%). Freedom from reoperation was 90%, 56%, 43%, and 14% at 10, 20, 25, and 30 years, respectively. At most recent follow-up the was only death, which was related to severe biventricular failure 25 years after conduit implant. CONCLUSIONS: PVR using a xenograft valved conduit results in prolonged freedom from reoperation and excellent long-term survival. These data, which provide long-term follow-up information on xenograft valves after PVR.

Training in paediatric cardiac surgery and the American Board of Thoracic Surgery.

Congenital heart surgery has evolved into its own specialty requiring unique techniques and skills. Recognizing the need to establish a special certification in congenital heart surgery, the American Board of Thoracic Surgery began the process in 2005, eventually granting the first certifications to qualified applicants in 2009. The American Council for Graduate Medical Education and the Thoracic Surgery Residency Review Committee have now approved specific training programs throughout the United States that will help to ensure the proper training of congenital heart surgeons for the future.

The University of Michigan Cardiac and Thoracic Surgery Program.

In 1928, the University of Michigan opened its thoracic surgery residency under the leadership of Dr John Alexander. Initially tasked with providing surgical care for patients with thoracic diseases such as tuberculosis, thoracic surgery subspecialties now provide surgical treatment for a spectrum of diseases, ranging from congenital cardiopulmonary abnormalities to thoracic malignancy to acquired heart and great vessel diseases. Both the residency and the medical center have evolved to mirror the changing practice of thoracic surgery.

Quality-Cost Relationship in Congenital Heart Surgery.

BACKGROUND: There is an increasing focus on optimizing health care quality and reducing costs. The care of children undergoing heart surgery requires significant investment of resources, and it remains unclear how costs of care relate to quality. We evaluated this relationship across a multicenter cohort. METHODS: Clinical data from The Society of Thoracic Surgeons Database were merged with cost data from the Pediatric Health Information Systems Database for children undergoing heart surgery (2006 to 2010). Hospital-level costs were modeled using Bayesian hierarchical methods adjusting for case-mix, and hospitals were categorized into cost tertiles. The primary quality metric evaluated was in-hospital mortality. RESULTS: Overall, 27 hospitals (30,670 patients) were included. Median adjusted cost per case was $82,360 and varied fivefold across hospitals, while median adjusted mortality was 3.4% and ranged from 2.4% to 5.0% across hospitals. Overall, hospitals in the lowest cost tertile had significantly lower adjusted mortality rates compared with the middle and high cost tertiles (2.5% vs 3.8% and 3.5%, respectively, both p < 0.001). When assessed at the individual hospital level, most (75%) but not all hospitals in the lowest cost tertile were also in the lowest mortality tertile. Similar relationships were seen across the spectrum of surgical complexity. Lower cost hospitals also had shorter length of stay and trends toward fewer major complications. CONCLUSIONS: Lowest cost hospitals generally deliver the highest quality care for children undergoing heart surgery, although there is some variation in this relationship. This information is important in the design of initiatives aiming to optimize health care value in this population.

Left ventricular retraining: theory and practice.

Congenitally corrected transposition of the great arteries or l-transposition of the great arteries is characterized by discordance of both the atrioventricular and ventriculoarterial connections. Physiologic repair of associated conditions, whereby the morphologic right ventricle remains the systemic ventricle, has resulted in unsatisfactory long-term outcomes due to the development of right ventricular failure and tricuspid valve regurgitation. While intuitively attractive, anatomic repair also has inherent challenges and risks, particularly for those patients who present late and require left ventricular retraining. Although early and intermediate-term outcomes for anatomic repair have been encouraging, longer-term follow-up has demonstrated concern for late left ventricular dysfunction in this subgroup of patients. Continued monitoring of this challenging patient population will clarify late outcomes and inform clinical management in the future.

Long-Term Survival and Reintervention After the Ross Procedure Across the Pediatric Age Spectrum.

BACKGROUND: There are limited data regarding long-term outcomes after the Ross procedure in children. We evaluated mortality and reintervention in a large pediatric cohort. METHODS: A retrospective analysis of all patients aged younger than 18 years who underwent the Ross procedure at our institution (1991 to 2013) was conducted. Kaplan-Meier curves and Cox proportion hazard models were used to evaluate long-term outcomes and associated risk factors. RESULTS: Included were 240 consecutive patients undergoing a Ross/Ross-Konno procedure: 18% infants, 48% children, and 33% adolescents. Infants were more likely to have complex left heart disease (p = 0.005). Overall survival to hospital discharge was 96%; infants had the highest mortality (18%). Long-term survival status was known for 99.6% (median follow-up, 10.7 years). Overall 15-year survival was 87% (lowest in infants, 72%; p = 0.003). Reintervention status was known in 87%. Overall 15-year freedom from any left ventricular outflow tract reintervention was 59%; 85% still had their autograft valve at the latest follow-up. Left ventricular outflow tract reintervention was uncommon in infants (n = 2). Overall 15-year freedom from right ventricular outflow tract reintervention was 53%, and was lower in infants (19%) than in children (51%) and adolescents (76%; p < 0.0001). CONCLUSIONS: Outcomes after the Ross procedure in children vary by age. Infants more commonly have complex left heart disease and experience higher mortality but have excellent long-term autograft durability. Children and adolescents have higher rates of left ventricular outflow tract reintervention, whereas infants are at highest risk of right ventricular outflow tract reintervention.

Personal glimpses into the evolution of truncus arteriosus repair.

Truncus arteriosus (common arterial trunk) is an uncommon but complex congenital heart anomaly. Until the early 1970s, typically, patients died between the age of a few weeks to six months. Congestive heart failure owing to large pulmonary blood flow and truncal valve regurgitation was the major cause of death until innovative surgical techniques were discovered. In 1963, Herbert Sloan at the University of Michigan completed the first repair using a nonvalved conduit with long-term survival (not reported until 1974). At the Mayo Clinic, Rastelli and McGoon studied and completed the first repair with a valved homograft in 1967. In 1976, Ebert used the 12-mm Hancock valved conduit in infants under six months of age (University of California, San Francisco). In Boston (mid-1980s), Jonas and Castañeda used aortic homografts, which greatly reduced bleeding as a postoperative complication. In the early 1990s, Bove (University of Michigan) reported outstanding results with an approach based on primary repair within the first few days of life for patients with truncus arteriosus. Improved prognosis for patients with truncus arteriosus resulted from these corrective operations by analyzing the natural history of this condition while applying innovative ideas, improved technology, and perioperative care.

Association of complications with blood transfusions in pediatric cardiac surgery patients.

BACKGROUND: Blood product transfusion during cardiopulmonary bypass has been demonstrated to be associated with increased morbidity and mortality in adult cardiac surgery populations. The aim of this study was to characterize the risk-adjusted occurrence of postoperative complications and mortality in relation to intraoperative blood product transfusion in our pediatric cardiac surgery population. METHODS: A retrospective review was performed on 1,631 consecutive cardiopulmonary bypass cases to determine the effects of intraoperative blood product transfusion on selected outcomes. After adjusting for patient and operative risk factors, multivariate analysis was performed to determine the association between blood product transfusion and postoperative complications. Cox proportional hazards model was used to examine the relationship of packed red blood cell transfusion to hospital length of stay. RESULTS: Red blood cell and fresh frozen plasma transfusion was associated with pulmonary complications (adjusted odds ratio, 1.55; 95% confidence interval, 1.05 to 2.28; p=0.03). Red blood cell transfusion also correlated with prolonged hospital stay (p<0.01). Cryoprecipate transfusion was associated with postoperative pulmonary complications (adjusted odds ratio, 1.79; 95% confidence interval, 1.13 to 2.55; p=0.01), but decreased incidence of 30-day mortality (adjusted odds ratio, 0.44; 95% confidence interval, 0.23 to 0.85; p=0.02). Platelet transfusion was associated with decreased 30-day mortality (adjusted odds ratio, 0.51; 95% confidence interval, 0.28 to 0.93; p=0.04), but not overall mortality. CONCLUSIONS: Blood product transfusion was associated with an increased incidence of postoperative pulmonary complications and prolonged hospital length of stay, but not overall mortality. These findings suggest that minimizing blood product transfusion would be beneficial in the pediatric cardiopulmonary bypass surgery patient population.

Pattern of recovery for transient complete heart block after open heart surgery for congenital heart disease: duration alone predicts risk of late complete heart block.

Transient complete heart block (TCHB) is defined as complete interruption of atrioventricular conduction (AVC) after cardiac surgery followed by return of conduction. This study aimed to assess the risk for the development of late complete heart block (LCHB) after recovery of TCHB and to examine the electrocardiographic and electrophysiologic properties of the AVC system after TCHB. Of the 44 patients in this study who experienced TCHB, 37 recovered completely. Seven patients progressed from TCHB to intermittent CHB or LCHB requiring pacemaker implantation. Preoperative, early postoperative, and late postoperative electrocardiograms as well as postoperative atrial stimulation were obtained. The results showed that the median duration of TCHB was 5 days in the TCHB group compared with 9 days in the LCHB group (p = 0.01). All 37 subjects with TCHB recovered AVC within 12 days, but only two with LCHB did so (p = 0.02). The risk of LCHB for the patients with 7 days of postoperative TCHB or longer was 13 times greater than for the patients with fewer than 7 days of TCHB (p = 0.01). The median late postoperative PR interval was slightly but significantly longer in the LCHB group than in the TCHB group (p = 0.02). In contrast, the electrophysiologic properties between the two groups did not differ significantly. From those findings, we concluded that delayed recovery of AVC after surgical TCHB (≥7 days), but not electrophysiologic properties of recovered AVC assessed early in the postoperative period strongly, predicts risk of LCHB. Follow-up evaluation of AVC is particularly indicated for the delayed recovery group.

Right ventricular outflow tract strategies for repair of tetralogy of Fallot: effect of monocusp valve reconstruction.

OBJECTIVES: The absence of a pulmonary valve (PV) after tetralogy of Fallot (TOF) repair has been shown to impact postoperative right ventricular (RV) function. The purposes of this study were to (i) compare early outcomes after PV-sparing vs transannular patching (TAP) with monocusp valve reconstruction or TAP alone and (b) assess the mid-term results after polytetrafluoroethylene (PTFE) membrane monocusp reconstruction. METHODS: From 2003 to 2009, 163 patients underwent TOF repair. Sixty-nine patients (42.3%) underwent a PV-sparing procedure (Group A), 74 (45.4%) underwent PTFE membrane monocusp valve reconstruction (Group B) and 20 (12.3%) underwent TAP only (Group C). Early outcomes were evaluated by the right-to-left ventricular pressure ratio, RV outflow tract gradient, tricuspid and PV function, intensive care unit (ICU) parameters and need for reintervention. Group B patients were also evaluated at intermediate term for clinical and echocardiographic parameters, including tricuspid and monocusp valve function and mobility. RESULTS: The median age, weight and PV Z-value of Group B patients were significantly lower; 20.5 months, 9.3 kg and -4, respectively. Postoperatively, the right-to-left ventricular pressure ratio was <0.5 in all groups. Mechanical ventilation time, fluid drainage duration and total ICU stay showed no significant difference between Groups A and B, while Group C was significantly longer (P < 0.01). There were five (3%) early deaths: three from Group A and two from Group B. The incidences of moderate or severe pulmonary insufficiency (PI) on discharge were 8.2% in Group A, 9% in Group B and 50% in Group C (P < 0.001). Among Group B patients, 85% of the evaluated patients had less than moderate PI in the intermediate-term follow-up, QRS duration <140 ms in 83.3% and right-to-left ventricular diameter ratio of 0.6 ± 0.2. Two (2.6%) patients underwent reoperation for monocusp replacement. There were two (2.7%) mid-term deaths. CONCLUSIONS: The use of a PTFE membrane monocusp valve and a valve-sparing strategy prevents immediate PI and improves short-term clinical outcomes. PTFE membrane monocusp appears advantageous in preventing severe intermediate-term PI and facilitates the preservation of RV function.

Extended single-patch repair of supravalvar aortic stenosis: a simple and effective technique.

BACKGROUND: The optimal surgical procedure for repair of supravalvar aortic stenosis (SVAS) remains uncertain. Proponents of multisinus repair techniques suggest improved outcomes compared with the single-patch technique. We evaluated the outcomes after an extended single-patch technique for relief of SVAS. METHODS: A cross-sectional retrospective analysis was performed of all SVAS patients who underwent repair from 1996 to 2009. Patient, procedural, and hospital course data were obtained through a review of the medical records. At follow-up, patients were evaluated for residual SVAS gradient, valvar aortic stenosis, aortic insufficiency, and need for reintervention. RESULTS: Twenty-two patients (mean age, 2.4 ± 2.4 years) underwent repair of SVAS (discrete form, 59%). Mean preoperative peak gradient was 77 ± 27 mm Hg (range, 20 to 139 mm Hg). There were no hospital deaths. Median postoperative length of stay was 5 days (range, 3 to 68 days). Mean follow-up was 4.1 ± 3.5 years (range, 0.7 to 13 years). Follow-up Doppler echocardiography revealed a peak left ventricular outflow tract gradient of 10 ± 12 mm Hg (range, 0 to 41 mm Hg). No patient had significant valvar aortic stenosis or insufficiency. Two patients (9%) required catheter-based reintervention that was unrelated to the SVAS repair. CONCLUSIONS: This study demonstrates that a simple, extended single-patch technique for repair of SVAS provides excellent medium-term results. A durable reduction in gradient with low complication and recurrence rates can be achieved without the need for more complicated multisinus patch repairs.

A method of transcutaneously adjustable pulmonary artery banding for staged left ventricular retraining.

OBJECTIVES: The placement of a pulmonary artery band to retrain the left ventricle often requires reoperation for band adjustment. We describe an effective technique for the placement of a transcutaneously adjustable pulmonary artery band that allows adjustments to be made without the need for repeat sternotomy. METHODS: Using standard catheters, an adjustable band was fashioned and placed around the pulmonary artery with the control end positioned in the subcutaneous tissue of the anterior chest wall. Tightening or loosening of the band can be subsequently performed by exposing the control end without the need for reopening the chest. RESULTS: From 1995 to 2011, 11 patients underwent placement of a transcutaneously adjustable pulmonary artery band for the purpose of retraining the morphologic left ventricle for a subsequent arterial switch operation. One or more band adjustments were required in 6 patients (1 loosened and 5 tightened, 55%) at a mean of 281 days (median, 98; range, 0-917) after initial band placement. All were accomplished successfully by exposing the band in the subcutaneous tissue of the anterior chest wall and performing the adjustment under Doppler echocardiographic guidance. CONCLUSIONS: This technique affords the operating surgeon the freedom to apply the band very gradually, erring on the side of safety, and facilitates a gradual increase in ventricular afterload that can be performed as a minor procedure.