Osama Eltayeb

Performance of SynerGraft Decellularized Pulmonary Homograft in Patients Undergoing a Ross Procedure

BACKGROUND In the Ross aortic valve replacement (AVR), a pulmonary allograft normally replaces the autotransplanted pulmonary valve. Despite the Ross advantages vs other AVR procedures, there has been a small but unpredictable risk of early structural allograft valve deterioration, usually manifested by shrinkage and right ventricular outflow tract obstruction. This study analyzed our results of the Ross AVR using a new CryoValve SynerGraft (CryoLife Inc, Kennesaw, GA) decellularized pulmonary allograft (SGDPA) and compared it with the standard cryopreserved allograft (SCA) used during the same period. METHODS Between 2000 and 2009, 29 patients received a SGDPA and 34 received the SCA during Ross AVR. Patients were a mean age at implant of 28.6 ± 16.0 years (range, 4 months to 58 years). Retrospective data included reported adverse events, and the most recent hemodynamic data were collected. RESULTS No early or late deaths or significant morbid events occurred during the mean follow-up of 4.9 ± 2.7 years (range, 2 months to 9 years). No patient required conduit reoperation. The median peak gradient at discharge was 12 mm Hg and was not significant at last follow-up. No deterioration in conduit valve function occurred in the SGDPA group. Mild conduit regurgitation developed in several SCA patients, and one patient had moderate regurgitation. No patient reached our definition of conduit dysfunction (peak gradient: 40 mm Hg or >2+ regurgitation). CONCLUSIONS The SGDPA conduit is an alternative to the SCA for the Ross AVR. The early clinical and hemodynamic results are encouraging but were not significantly different from the SCA. SynerGraft technology may provide a more durable option for patients who need right ventricular outflow tract reconstruction. Further long-term follow-up is needed to see if this decellularization process improves long-term allograft durability.

Surgical valvuloplasty versus balloon aortic dilation for congenital aortic stenosis: Are evidence-based outcomes relevant?

BACKGROUND For children with congenital aortic stenosis (AS) who are selected for biventricular repair, valvuloplasty can be achieved by surgical aortic valvuloplasty (SAV) or by transcatheter balloon aortic dilation (BAD). A retrospective study was undertaken to compare the effectiveness of BAD versus SAV, evaluating the long-term survival, incidence of aortic valve restenosis or aortic insufficiency (AI) or both, and freedom from reoperation for repeated valve repair or replacement. Neonates less than 2 months of age were excluded from this comparison. METHODS We reviewed the outcomes of children undergoing repair by SAV (n = 89) and BAD (n = 69) at our institution during a recent 20-year period. Clinical and echocardiographic follow-up were analyzed. The patient groups were compared with regard to the persistence or recurrence of postoperative aortic gradients and valve insufficiency and valve-related reintervention, including aortic valve replacement (AVR). RESULTS There was no significant difference between the groups with respect to mean age, body surface area, valve anatomy, sex, and preoperative gradients. Our data demonstrate that gradient reduction, AI, and the need for reintervention were worse for BAD. Aortic gradients at last follow-up were similar in both cohorts, but return of a significant gradient occurred sooner for patients who had BAD. Aortic gradient at discharge was significantly better for the patients who underwent SAV. Kaplan-Meier analysis showed that at 10 years, comparison of SAV and BAD was as follows: freedom from reintervention, 72% versus 53% (p = 0.02) and freedom from AVR, 80% versus 75% (p = 0.32). CONCLUSIONS BAD yields less gradient reduction, more postprocedural AI, and a shorter interval between initial and subsequent reintervention than does SAV. Our results demonstrate that SAV is safe and effective and that residual gradients and degree of AI are low. After SAV, the need for AVR can usually be delayed until the child is significantly older. The long-term functional stability after SAV is excellent. BAD in comparison is associated with an increased frequency and severity of AI and the need for earlier reintervention and valve replacement. SAV should be offered to all patients beyond the newborn period because it gives superior and longer lasting palliation.

Evolution of mitral valve replacement in children: A 40-year experience

BACKGROUND This report reviews our 40-year experience with pediatric mitral valve replacement (MVR) with respect to mortality, valve-related morbidity, and reoperation risk factors. METHODS From 1970 to 2010, 97 patients have undergone a total of 136 MVRs. Median age was 8 years (2 weeks to 18 years), 41 patients (42%) were less than 5 years, and 16 were infants (17%). Etiology was congenital in 65 patients (67%), rheumatic in 27 (28%), and endocarditis in 5 (5%). Regurgitation was the predominant lesion in 67 patients (69%), stenosis in 23 (24%), and mixed in 7 (7%) patients. Mechanical valves (ball, n=11; or bileaflet disc, n=66) and xenografts (porcine, n=14; bovine, n=2) were used in 93 initial MVR patients. Since 2002, 5 children have undergone Ross MVR with a pulmonary autograft in 3 and an aortic homograft in 2. RESULTS Hospital mortality was 6% (6 of 97). There were 23 late deaths and 5 patients have required cardiac transplantation. Thirty-five year actuarial survival was 71%. Age less than 2 years, MVR prior to 1980, atrioventricular septal defect, univentricular heart, and additional left side obstructions were significant predictors of death. Mean follow-up was 12.8±10.1 years (range, 2 months to 38 years). Seventeen patients with mechanical valves experienced systemic emboli in 9 (10%), valve thrombosis in 5 (6%), and bleeding requiring transfusion in 3 (3%) patients. Thirty-two patients required reoperations (35%) from 3 months to 14 years (mean, 6.5±4.4 years) after initial MVR. Actuarial freedom from reoperation at 35 years was 63%. Variables associated with mitral re-replacement were younger age, small weight, valve diameter less than 23 mm, MVR prior to 1980, and type of implanted valves (xenograft, single-leaflet disk, ball-caged, or human valves). CONCLUSIONS Pediatric MVR can be performed with low initial mortality but should be reserved for medical and reconstruction failure because reoperation, valve-related complications, and late mortality are high. Bileaflet prostheses larger than 23 mm have the lowest reoperation risk. Ross MVR may offer select patients a durable tissue valve without lifelong anticoagulation and its associated complications.

Outcomes of interrupted aortic arch repair using the carotid artery turndown procedure.

OBJECTIVE Interrupted aortic arch is a rare congenital anomaly affecting 1.5% of infants with congenital heart disease. Multiple surgical modalities exist to address this defect. We evaluate the long-term outcome of interrupted aortic arch with the left carotid artery turndown technique from a single institution. METHODS Patients with interrupted aortic arch who underwent the carotid turndown procedure were identified between September 1982 and March 2010. Medical and surgical records were reviewed. Mortality data were obtained from state death records. RESULTS Forty-seven patients met inclusion criteria. Median follow-up was 6.2 years (5 days to 23.2 years). Twenty-one patients (45%) had genetic syndromes. There were 4 operative deaths (8.5%) and 9 late deaths (19%). One-year and 5-year survivals were 80.2% and 72.6%, respectively. Seventeen patients (36.2%) required reoperation or other interventions on the aortic arch. CONCLUSIONS Left carotid artery turndown offers a favorable surgical outcome. It compares with end-to-end repair, while providing a tension-free anastomosis and avoiding neonatal circulatory arrest and cardiopulmonary bypass. Disadvantages include a 2-stage repair and a significant reintervention rate, particularly when compared with the aortic arch advancement technique. Nevertheless, the reduced exposure to circulatory arrest and bypass and avoidance of left bronchial obstruction are important considerations that may offset these limitations.

Contegra Versus Pulmonary Homografts for Right Ventricular Outflow Tract Reconstruction: A Ten-Year Single-Institution Comparison

Objective: Repair of congenital heart defects involving the right ventricular outflow tract (RVOT) may require pulmonary valve replacement at the time of primary repair or reoperation. This study compares the outcomes of bovine jugular vein grafts (BJV, Contegra, Medtronic Inc.) with cryopreserved pulmonary homografts (PHs) in patients with RVOT obstruction at a single institution. Methods: We reviewed the outcomes of all BJVs and PHs implanted for RVOT reconstruction from 1999 to 2010. Echocardiographic data were reviewed to evaluate valve performance. Graft dysfunction is defined as RVOT obstruction with peak echo-Doppler gradient >40 mm Hg and/or grade III/IV conduit valve regurgitation. Graft failure is defined as need for conduit replacement or need for catheter or surgical reintervention. Results: A total of 216 patients who received BJVs (n = 153) and PHs (n = 63) were studied. There was no significant difference between the groups with respect to mean age, body surface area, conduit indication, or conduit diameter, though mean follow-up duration was longer in patients that received homografts. Conduit dysfunction and conduit failure and need for explantation were worse for homografts, albeit at longer follow-up interval. Distal stenosis and actuarial survival were similar. Conclusions: In the first ten years after pulmonary implantation of BJVs and PHs, survival and freedom from distal stenosis are statistically similar, but freedom from failure, dysfunction, and explantation are significantly better for BJV conduits. The BJV conduit is a good alternative in patients who require RVOT reconstruction.

Aortic Implantation of Anomalous Origin of the Left Coronary Artery From the Pulmonary Artery: Long-Term Outcomes

BACKGROUND Since 1989 all patients with anomalous origin of the left coronary artery from the pulmonary artery at our institution have been treated with aortic implantation. The purpose of this review was to assess the late outcomes of these patients, especially regarding left ventricular (LV) function and mitral valve insufficiency. METHODS Between 1989 and 2014, 36 patients had aortic implantation of anomalous origin of the left coronary artery from the pulmonary artery. Mean age at surgery was 2.5 ± 5.1 years (median, 0.5 years). Operative strategy included antegrade cold-blood cardioplegia, main pulmonary artery transection, aortic implantation with a large button of pulmonary artery, pulmonary reconstruction with fresh autologous pericardium, and prolonged postoperative inotropic and ventilator support. Mitral regurgitation and LV dysfunction were graded as 0 to 4 (0 = none, 1 = trivial, 1.5 = trivial-mild, 2 = mild, 2.5 = mild-moderate, 3 = moderate, 3.5 = moderate-severe, and 4 = severe). RESULTS Mean mitral regurgitation grade preoperatively was 2.95 ± 0.95. Mean LV dysfunction grade was 3.14 ± 1.27. Mean cross-clamp and cardiopulmonary bypass times were 49.1 ± 18 minutes (median, 48.5 minutes) and 147.5 ± 45 minutes (median, 139 minutes), respectively. There was no operative or late mortality. Four patients had delayed sternal closure. Mean duration of ventilator support was 11 ± 6.6 days (median, 9 days). Two patients required 3 and 6 days of postoperative extracorporeal mechanical circulatory support. Mean length of stay was 25 ± 18 days (median, 19 days). No patient has required reoperation for supravalvar pulmonary stenosis, coronary stenosis, or mitral valve repair or replacement. Late echocardiographic follow-up shows a mean mitral regurgitation grade of 1.67 ± 1.05 and a mean LV dysfunction grade of 0.23 ± 0.68. CONCLUSIONS Aortic implantation is our procedure of choice for patients with anomalous origin of the left coronary artery from the pulmonary artery. No patient required mitral valve repair or transplant. There was marked improvement of mitral regurgitation grade, return to essentially normal LV function, and no mortality during a 25-year period.

Successful Bridge‐to‐Transplant of Functionally Univentricular Patients With a Modified Continuous‐Flow Ventricular Assist Device

A continuous flow extracorporeal ventricular assist device (VAD) was modified to support functionally univentricular infants and children awaiting heart transplantation. A centrifugal VAD, designed to flow from 1.5 to 8 L/min, was used as a bridge-to-transplant in four patients with functionally univentricular circulation. A variable restrictive recirculation shunt permitted lower flow ranges in small patients. In hypoxic patients, an oxygenator was incorporated into the circuit. From 2012 to 2015, the modified VAD was placed in four patients with Glenn physiology. Age ranged from 0.97 to 6.98 years (median = 2.2 yrs). Body surface area ranged from 0.41 to 0.84 m2 (median = 0.54 m2 ). One patient was on extracorporeal membrane oxygenation prior to VAD. A recirculation shunt was used in three patients. Three patients required temporary use of an oxygenator for 4, 10, and 27 days. Median time on the VAD was 32.3 days (range = 23-43 days). A decrease in the cavopulmonary pressure was noted in all patients, as was a fall in the B-type natriuretic peptide. Three patients survived transplant and were discharged at 28-82 days post-transplantation. One patient died after 35 days of support. Two patients experienced major bleeding events. Two patients experienced cerebrovascular accidents, one major and one minor. The centrifugal VAD successfully supported palliated functionally univentricular patients awaiting heart transplantation. The modified recirculation shunt facilitated the successful support of patients in whom optimal flows were substantially lower than that recommended by the manufacturer. The continuous-flow VAD effectively decompressed the cavopulmonary system. The design allowed placement of an in-line oxygenator in hypoxic patients. Further investigation is required to decrease the thromboembolic events, and associated morbidity, in patients supported with this device.

Modified Single Patch: Are We Still Worried About Subaortic Stenosis?

BACKGROUND When the modified single-patch technique for atrioventricular septal defect (AVSD) repair was introduced by Dr Benson Wilcox, there was concern that these patients might be at risk for late subaortic stenosis and left ventricular outflow tract obstruction (LVOTO). This review evaluated our modified single-patch population for LVOTO in the postoperative period. METHODS Between January 2000 and 2013, 77 infants underwent AVSD repair with a modified single-patch technique. Median age was 4.2 months, and median weight was 5 kg. Eight patients had a prior repair of coarctation of the aorta via left thoracotomy in the newborn period. RESULTS The median hospital stay was 10 days. No patient required a pacemaker. The mean and median follow-up times were 4.6 and 3.7 years, respectively. Only 2 patients (2.5%) required reoperation for LVOTO; both had prior repair of coarctation of the aorta (2 of 8 vs 0 of 69, p = 0.01). A discrete fibrous subaortic membrane developed in the first patient that required resection at 3 and 7 years after repair. The other patient had LVOTO from accessory chordae of the left atrioventricular valve and required mitral valve replacement 5 months after repair. One early death occurred at 4 months postoperatively due to liver failure related to hyperalimentation. CONCLUSIONS At intermediate term follow-up, LVOTO does not appear to be a significant postoperative issue after modified single-patch repair of AVSD. Coarctation of the aorta was the most significant predictor of late LVOTO after repair of AVSD with the modified single-patch technique.

Metabolic Uncoupling Following Cardiopulmonary Bypass

OBJECTIVE The objective of this study was to characterize the natural history of metabolic uncoupling (type B hyperlactemia and hyperglycemia) following cardiopulmonary bypass (CPB), and to determine the impact of insulin therapy on time to lactate normalization in patients without low cardiac output. DESIGN The design used was a retrospective cohort study. SETTING The study was set in a pediatric cardiac intensive care unit in a tertiary-care urban childrens hospital. PATIENTS All patients were aged ≤21 years admitted between 2007 and 2013 following cardiac surgery involving CPB with empiric intraoperative corticosteroids. ELIGIBILITY CRITERIA simultaneous hyperlactemia (≥3.5 mEq/L) and hyperglycemia (≥200 mg/dL) within 48 hours after bypass. EXCLUSION CRITERIA Exclusion criteria were evidence of low cardiac output state, diabetes or postoperative steroid administration. INTERVENTIONS Characteristics were compared between those treated with insulin and those who were not (controls). OUTCOME MEASURES Outcome measures used were time from admission to onset of hyperglycemia and hyperlactemia and time to resolution. Clinical outcomes included duration of mechanical ventilation, length of stay, unplanned readmission/reoperation, hypoglycemia and death. RESULTS Of the 1345 patients receiving CPB, 132 (9.8%) met inclusion criteria. Seventy-eight (59%) were treated with insulin, leaving 54 controls. Patient characteristics, surgical complexity and time to onset of hyperglycemia and hyperlactemia were similar between groups. The insulin group had a shorter duration of hyperglycemia. There was no significant difference between groups in time to lactate normalization, ventilator days, length of stay, readmission and reoperation rates. Hypoglycemia (<60 mg/dL) occurred in three patients. CONCLUSIONS In children with metabolic uncoupling after CPB, insulin use did not shorten the time to lactate normalization or alter clinical outcomes. These findings suggest that type B hyperlactemia with hyperglycemia after CPB will resolve spontaneously and does not warrant specific treatment.

Brom Aortoplasty for Supravalvular Aortic Stenosis

Background: Controversy remains regarding the optimal surgical approach for children with supravalvular aortic stenosis (SVAS). Methods: Since 1997 we have used Brom three-patch aortoplasty for patients with SVAS. We prefer computed tomography (CT) imaging for preoperative evaluation rather than cardiac catheterization as it avoids the well-known morbidity of general anesthesia. The purpose of this study was to present our intermediate-term results of this strategy. Results: Twenty consecutive patients with SVAS were treated with Brom aortoplasty. Mean age was 3.7 ± 5.9 years (median, 1.5 years). Twelve patients had Williams syndrome. Ten patients had preoperative advanced medical imaging (seven CT, three magnetic resonance imaging) and did not have cardiac catheterization. Mean times for cardiopulmonary bypass and cross-clamp were 172 ± 29 minutes and 110 ± 21 minutes, respectively. Ten patients had simultaneous pulmonary artery stenosis patching. Median length of stay was seven days. There was no operative or late mortality. Mean follow-up was 6 ± 5 years. There were no reoperations on the aortic root. Fifteen patients had mild or less aortic insufficiency (AI) and two had moderate AI. One patient who had infant balloon dilation of the aortic valve and postoperative subacute bacterial endocarditis had moderate-to-severe AI and aortic stenosis (AS). One patient had moderate residual SVAS; all others had no AS. No patients had late coronary insufficiency. Conclusion: Brom aortoplasty promotes restoration of normal aortic root geometry and relief of coronary ostial stenosis, which is important in preventing myocardial ischemia. Computed tomography imaging is our preferred diagnostic modality. Intermediate-term outcomes are excellent with no recurrent SVAS, coronary events, or reoperations on the aortic valve.