Mark Galantowicz

Hybrid Approach for Hypoplastic Left Heart Syndrome: Intermediate Results After the Learning Curve

BACKGROUND Lessons learned during the development of a novel hybrid approach have resulted in a reliable, reproducible alternative treatment for hypoplastic left heart syndrome (HLHS). Herein we report our results using this hybrid approach in a uniform risk cohort. METHODS This is a review of prospectively collected data on patients treated for HLHS using a hybrid approach (n = 40) between July 2002 and June 2007. The hybrid approach includes pulmonary artery bands, a ductal stent, and atrial septostomy as a neonate, comprehensive stage 2 procedure resulting in Glenn shunt physiology at six months and Fontan completion at two years. RESULTS Forty patients had a hybrid stage 1 with 36 undergoing a comprehensive stage 2 procedure. Fifteen patients have completed the Fontan procedure with 17 pending. Overall survival was 82.5% (33 of 40). The seven deaths included one at stage 1, two between stages 1 and 2, three at stage 2, and one between stages 2 and 3. One patient had successful heart transplantation during the interstage period. CONCLUSIONS The hybrid approach can yield acceptable intermediate results that are comparable with a traditional Norwood strategy. Potential advantages of the hybrid approach include the avoidance of circulatory arrest and shifting the major surgical stage to later in life. These data provide the platform for a prospective trial comparing these two surgical options to assess whether there is less cumulative impact with the hybrid approach, thereby improving end organ function, quality, and quantity of life.

Lessons Learned from the Development of a New Hybrid Strategy for the Management of Hypoplastic Left Heart Syndrome

Despite improvements in surgical techniques and perioperative management, the overall results of traditional staged palliation for hypoplastic left heart syndrome (HLHS) remain suboptimal. We report the evolution of a hybrid strategy in 34 patients coupling innovative surgical and transcatheter techniques that requires one open-heart procedure to reach a Fontan completion. Experience has led to modifications in technique, timing of procedures, and follow-up. Current initial palliation is by intraoperative, off-pump, placement of bilateral pulmonary artery bands and a PDA stent. Transcatheter creation of an unrestricted atrial septal defect is performed when necessary. Follow-up includes weekly cardiology assessment, including echocardiography with a surveillance catheterization performed at 6 weeks. At 3-6 months a comprehensive stage 2 procedure (elements of traditional stages 1-3) is performed. At 2 years, transcatheter Fontan completion with a covered stent is performed. Initial hybrid stage 1 was from August 2001 to December 2004 and included 29 newborns (1.8-4.2 kg). There were five hospital deaths and three interstage deaths. Procedural and interstage deaths were eliminated in the latter half of the experience. Comprehensive stage 2 included 18 patients. There were four deaths; two patients who died were brought urgently to operation. Transcatheter Fontan completion included 5 patients (not from the initial 29); there were no deaths and all returned home in 24 hours. With this strategy there is one exposure to cardiopulmonary bypass, aortic cross-clamping, and circulatory arrest. There was a significant learning curve, which is highlighted. This initial experience warrants further investigation to determine whether this hybrid strategy will yield better short- and long-term outcomes.

Multicenter Experience with Perventricular Device Closure of Muscular Ventricular Septal Defects

Hybrid procedures are becoming increasingly important, especially in the management of congenital heart lesions for which there are no ideal surgical or interventional options. This report describes a multicenter experience with perventricular muscular venticular septal defect (VSD) device closure.Three groups of patients (n = 12) were identified: infants with isolated muscular VSDs (n = 2), neonates with aortic coarctation and muscular VSDs (n = 3) or patients with muscular VSDs and other complex cardiac lesions (n = 2), and patients with muscular VSDs and pulmonary artery bands (n = 5). Via a sternotomy or a subxyphoid approach, the right ventricle (RV) free wall was punctured under transesophageal echocardiography guidance. A guidewire was introduced across the largest defect. A short delivery sheath was positioned in the left ventricle cavity. An Amplatzer muscular VSD occluding device was deployed across the VSD. Cardiopulmonary bypass was needed only for repair of concomitant lesions, such as double-outlet right ventricle, aortic coarctation, or pulmonary artery band removal. No complications were encountered using this technique. Discharge echocardiograms showed either mild or no significant shunting across the ventricular septum. At a median follow-up of 12 months, all patients were asymptomatic and 2 patients had mild residual ventricular level shunts. Perventricular closure of muscular VSDs is safe and effective for a variety of patients with muscular VSDs.

Implantable left ventricular assist devices can successfully bridge adolescent patients to transplant

BACKGROUND Left ventricular assist devices (LVAD) have been used successfully as a life-sustaining bridge to transplantation in adults with end-stage heart failure. Long-term implantable cardiac assist devices for smaller adolescent patients are not yet available in the United States. METHODS This study reviews the experience with patients less than 21 years old that received HeartMate LVADs (TCI) at our institution. Twelve patients were implanted with 13 LVADs. The patients ranged in age from 11 to 20 years (mean 16 years). Body surface area ranged from 1.4 to 2.2 m2 (mean 1.8 m2). Patients were selected for LVAD placement based on eligibility for heart transplant and evidence of end-organ dysfunction. Device placement in small patients was facilitated with prosthetic graft abdominal wall closure. No patient received systemic anticoagulation. RESULTS The duration of LVAD support ranged from 0 to 397 days (mean 123 days). Seven of the 8 patients eligible for discharge from the hospital with a vented-electric LVAD were supported at home while awaiting transplantation. Outcomes of LVAD support were: LVAD explantation in 2 cases (15%), expiration with LVAD in place in 3 cases (23%), and successful transplantation in 8 cases (62%). Complications included 4 patients with systemic infection, 3 re-operations for hemorrhage, 1 embolic event, and 1 intraoperative air embolus that proved fatal. One explanted patient required a subsequent LVAD and the other expired 4 months after explantation. Six of the 8 transplanted patients are alive and well with follow-up ranging from 8 to 43 months. CONCLUSIONS Adolescent patients with heart failure can be successfully supported on a long-term basis to heart transplantation with the HeartMate LVAD. The wearable device allows for discharge home while awaiting transplantation. Device explantation without subsequent transplantation can be unpredictable. The incidence of thromboembolism remains low despite the absence of systemic anticoagulation. The technique of prosthetic graft closure of the abdominal wall facilitates the use of this device in smaller patients.

The Retrograde Aortic Arch in the Hybrid Approach to Hypoplastic Left Heart Syndrome

BACKGROUND Before palliative stage 2 for hypoplastic left heart syndrome, the coronary and cerebral circulations are often dependent on retrograde perfusion by means of the aortic arch. Results of hybrid palliation with a focus on patients exhibiting retrograde aortic arch obstruction (RAAO) were analyzed. METHODS From July 2002 to March 2008 66 consecutive hybrid procedures for hypoplastic left heart syndrome were performed. Patients requiring RAAO intervention based on cardiology-surgery consensus were defined as group 1 (n = 16), whereas all other hypoplastic left heart syndrome patients formed group 2 (n = 50). RESULTS At birth there were no differences between groups in terms of demographics or cardiac function. Group 1 had more patients with aortic atresia (94% versus 58%; p = 0.01), and 69% of patients had initial echocardiographic comments regarding incipient RAAO versus 26% in group 2 (p = 0.007). The type of ductal stent, balloon versus self-expandable, did not influence the subsequent development of RAAO. Before RAAO intervention (mean age, 74 days), group 1 patients had significantly more tricuspid regurgitation. The main treatment for RAAO in group 1 was coronary stent insertion, with 3 patients having a reverse central shunt. At a mean follow-up of 611 days, group 1 had reduced survival interstage (56.3% versus 88%; p = 0.005) and overall (43.7% versus 70%; p = 0.03). CONCLUSIONS Clinically important RAAO occurred in 24% of the hypoplastic left heart syndrome patients in this series. If RAAO is detected at birth or early interstage, a Norwood operation is now favored. Palliative interventional catheterization remains very important mid and late interstage for continuing the hybrid strategy toward comprehensive stage 2.

Atrial septal interventions in patients with hypoplastic left heart syndrome

Objectives: To report an institutional experience performing percutaneous atrial septal interventions in patients with hypoplastic left heart syndrome (HLHS). Background: The success of the Hybrid approach in palliating patients with HLHS is crucially dependant on relieving any significant interatrial restriction. Data on transcatheter interventions to relieve atrial septal restrictions in patients with HLHS are limited. Methods: We retrospectively reviewed 67 transcatheter atrial septal interventions that were performed between July 2002 and September 2007 in 56 patients with HLHS. The median weight was 3.35 kg. About 10.7% of patients had an intact atrial septum. Balloon atrial septostomy (BAS) was used in 77.6% of procedures, additional techniques in 35.8% of procedures. Patients were divided into those with standard atrial septal anatomy (group A, n = 33) and those with complex atrial septal anatomy (group B, n = 23). Results: The mean trans‐septal gradient was reduced significantly from 7 mm Hg to 1 mm Hg with the median time to discharge being 3.5 days. Major adverse events were seen in 8.9% of procedures, whereas minor adverse events occurred in 26.8% of procedures. Adverse events were significantly less common in patients with standard atrial septal anatomy, compared to those with complex atrial septal anatomy (25.6% versus 50.0%). About 19.6% patients required repeated atrial septal interventions. Survival up to and including Comprehensive stage II palliation was 73% group A, and 57% in group B. Conclusions: With utilization of appropriate techniques and equipment, atrial septal interventions in HLHS can be performed successfully in virtually all patients. Complex atrial septal anatomy is technically challenging and has a higher incidence of procedural adverse events. In the majority of patients, standard BAS can be performed safely, and is usually the only intervention required to achieve adequate relief of atrial septal restriction until Comprehensive stage II palliation.

Serial echocardiographic measurements of the pulmonary autograft in the aortic valve position after the Ross operation in a pediatric population using normal pulmonary artery dimensions as the reference standard.

Serial echocardiographic measurements of the annulus and sinus were obtained in children before the Ross operation, and early and late postoperatively. Values were compared with normal standards for the aorta and pulmonary artery (PA). There was no significant difference between PA annulus measurements before surgery and the corresponding autograft immediately afterward (1.73 +/- 0.60 cm preoperatively; 1. 63 +/- 0.58 cm postoperatively, p = NS). Late after surgery the mean annulus diameter was enlarged compared with the normal aorta (DeltaZ 1.9 +/- 2.4), but remained relatively unchanged compared with the normal PA (DeltaZ 0.7 +/- 1.1, p <0.01). In contrast, the autograft sinus was dilated early after surgery (1.83 +/- 0.58 cm preoperatively; 2.18 +/- 0.73 cm postoperatively, p <0.01). Mean sinus Z score further increased compared with both the aorta (DeltaZ 1.3 +/- 1.7) and PA (DeltaZ 1.3 +/- 1.6). Use of standard PA measurements may be important in the assessment of autograft enlargement. Minimal change in autograft Z scores over time suggests that annulus enlargement is mainly due to somatic growth. In contrast, the autograft sinus showed an immediate and continued disproportionate increase in size over time, suggesting that sinus enlargement is largely due to passive dilation.

The Role of Different Anesthetic Techniques in Altering the Stress Response During Cardiac Surgery in Children: A Prospective, Double-Blinded, and Randomized Study

Objectives: Our goal was to evaluate the role of three anesthetic techniques in altering the stress response in children undergoing surgery for repair of congenital heart diseases utilizing cardiopulmonary bypass in the setting of fast tracking or early tracheal extubation. Furthermore, we wanted to evaluate the correlation between blunting the stress response and the perioperative clinical outcomes. Design: Prospective, randomized, double-blinded study. Setting: Single center from December 2008 to May of 2011. Patients: Forty-eight subjects (low-dose fentanyl plus placebo, n = 16; high-dose fentanyl plus placebo, n = 17; low-dose fentanyl plus dexmedetomidine, n = 15) were studied between ages 30 days to 3 years old who were scheduled to undergo repair for a ventricular septal defect, atrioventricular septal defect, or Tetralogy of Fallot. Methods: Children undergoing surgical repair of congenital heart disease were randomized to receive low-dose fentanyl (10 mcg/kg; low-dose fentanyl), high-dose fentanyl (25mcg/kg; high-dose fentanyl), or low-dose fentanyl plus dexmedetomidine (as a 1 mcg/kg loading dose followed by infusion at 0.5mcg/kg/hr until separation from cardiopulmonary bypass. In addition, patients received a volatile anesthetic agent as needed to maintain hemodynamic stability. Blood samples were tested for metabolic, hormonal and cytokine markers at baseline, after sternotomy, after the start of cardiopulmonary bypass, at the end of the procedure and at 24 hours postoperatively. Measurements and Main Results: Forty-eight subjects (low-dose fentanyl plus placebo, n = 16; high-dose fentanyl plus placebo, n = 17; low-dose fentanyl plus dexmedetomidine, n = 15) were studied. Subjects in the low-dose fentanyl plus placebo group had significantly higher levels of adrenocorticotropic hormone, cortisol, glucose, lactate, and epinephrine during the study period. The lowest levels of stress markers were seen in the high-dose fentanyl plus placebo group both over time (adrenocorticotropic hormone, p= 0.01; glucose, p = 0.007) and at individual time points (cortisol and lactate at the end of surgery, epinephrine poststernotomy; p < 0.05). Subjects in the low-dose fentanyl plus dexmedetomidine group had lower lactate levels at the end of surgery compared with the low-dose fentanyl plus placebo group (p < 0.05). Although there were no statistically significant differences in plasma cytokine levels between the three groups, the low-dose fentanyl plus placebo group had significantly higher interleukin-6:interleukin-10 ratio at 24 hours postoperatively (p < 0.0001). In addition, when compared with the low-dose fentanyl plus placebo group, the low-dose fentanyl plus dexmedetomidine group showed a lower norepinephrine level from baseline at poststernotomy, after the start of cardiopulmonary bypass, and at the end of surgery (p ⩽ 0.05). Subjects in the low-dose fentanyl plus placebo group had more postoperative narcotic requirement (p = 0.004), higher prothrombin time (p ⩽ 0.03), and more postoperative chest tube output (p < 0.05). Success of fast tracking was not significantly different between groups (low-dose fentanyl plus placebo 75%, high-dose fentanyl plus placebo 82%, low-dose fentanyl plus dexmedetomidine 93%; p = 0.39). Conclusions: The use of low-dose fentanyl was associated with the greatest stress response, most coagulopathy, and highest transfusion requirement among our cohorts. Higher dose fentanyl demonstrated more favorable blunting of the stress response. When compared with low-dose fentanyl alone, the addition of dexmedetomidine improved the blunting of the stress response, while achieving better postoperative pain control.

Assessment of Quality of Life in Young Patients with Single Ventricle after the Fontan Operation

OBJECTIVES To assess self-reported quality of life (QOL) in a large multicenter cohort of adolescent and young adults surviving Fontan. STUDY DESIGN Cross-sectional. The Pediatric Quality of Life Inventory (PedsQL) was administered to 408 survivors of Fontan ages 13-25 years enrolled in the Pediatric Heart Network Fontan Follow-up Study. Subjects also completed either the Child Health Questionnaire (age <19 years) or Short Form Health Survey (age ≥ 19 years). PedsQL data were compared with matched controls without a chronic health condition. Correlations between the measures were examined. RESULTS Mean PedsQL scores for subjects receiving Fontan were significantly lower than those for the control group for physical and psychosocial QOL (P < .001). Overall, 45% of subjects receiving Fontan had scores in the clinically significant impaired range for physical QOL with 30% in the impaired range for psychosocial QOL. For each 1 year increase in age, the physical functioning score decreased by an average of 0.76 points (P = .004) and the emotional functioning score decreased by an average of 0.64 points (P = .03). Among subjects ≥19 years of age, the physical functioning score decreased by an average of 2 points for each year increase in age (P = .02). PedsQL scale scores were significantly correlated with conceptually related Child Health Questionnaire (P < .001) and Short Form Health Survey scores (P < .001). CONCLUSIONS Survivors of Fontan are at risk for significantly impaired QOL which may decline with advancing age. Routine assessment of QOL is essential to inform interventions to improve health outcomes. The PedsQL allowed QOL assessment from pediatrics to young adulthood. TRIAL REGISTRATION ClinicalTrials.gov: NCT00132782.

Necrotizing enterocolitis in neonates undergoing the hybrid approach to complex congenital heart disease.

Objective: To investigate the prevalence of necrotizing enterocolitis (NEC) in neonates undergoing the Stage I hybrid procedure for palliation of complex congenital heart disease (CHD). Neonates undergoing the Norwood surgery for hypoplastic left-heart syndrome have the highest risk for NEC of all CHD patients. The hybrid procedure is another palliative option for hypoplastic left-heart syndrome, but NEC in neonates undergoing this procedure has not been reported. Design: Retrospective chart review of 73 neonates who underwent the hybrid procedure for palliation of complex CHD. Demographic, perinatal, perioperative, clinical, and procedural data were collected. NEC was defined as modified Bells Stage II and above. Setting: The cardiothoracic and neonatal intensive care units in a large free-standing childrens hospital. Patients: All neonates who underwent the hybrid Stage I procedure for the palliation of complex CHD from April 2002 through April 2008. Measurements and Main Results: Seventy-three neonates were reviewed and 11.0% (eight of 73) developed NEC. Of the patients with NEC, 37.5% (three of eight) died and two patients required abdominal surgery. Earlier gestational age (<37 wks), lower maximum dose of prostaglandin infusion, and unexpected readmission to the intensive care unit were statistically associated with NEC (p = .009, 0.02, and 0.04, respectively). No other demographic, perinatal, perioperative, clinical, or procedural variables were associated with the development of NEC in this patient population, including enteral feeding regimens, umbilical artery catheters, inotrope use, and average oxygen saturation and diastolic blood pressure. Conclusions: The prevalence of NEC in patients undergoing the hybrid procedure is comparable to that reported for neonates undergoing the Norwood procedure. Earlier gestational age is a significant risk factor for NEC in patients who undergo the hybrid Stage I procedure. Multidisciplinary approaches to better understand abdominal complications and to develop feeding regimens in neonates undergoing the hybrid approach to complex CHD are needed to improve outcomes and decrease morbidities.