Predictors of ductus arteriosus in-stent stenosis in the hybrid approach to hypoplastic left heart syndrome.

The hybrid approach to palliation of hypoplastic left heart syndrome using pulmonary artery bands, a patent ductus arteriosus (PDA) stent, and atrial septostomy has been well described. One potential complication of hybrid stage 1 palliation is the development of neointimal formation and in-stent stenosis (ISS). This study aimed to identify predictors of ISS development. Patients who underwent hybrid stage 1 palliation between 2002 and 2010 were included in the study. The clinical information included oxygen saturation, weight, vital signs, and medications. Echocardiographic data included ventricular function, degree of tricuspid regurgitation, and velocity through the PDA stent and pulmonary artery bands. Hemodynamic data from interstage catheterizations were similarly noted. Patients who developed clinically significant ISS requiring either transcatheter intervention or early stage 2 repair were compared with those who did not. Of the 66 patients included in the study, 40 were boys (61 %). The median age at hybrid palliation was 7 days (range, 1-93 days), and the median initial weight was 3.2 kg (range, 1.4-5 kg). In 13 patients (20 %), ISS developed. The mean initial weight was significantly greater in the ISS group (3.5 ± 0.5 vs. 3.0 ± 0.6 kg) (p = 0.03). The mean oxygen saturations did not differ significantly between the no-ISS group (82.2 % ± 5.7 %) and the ISS group (81.4 % ± 2.0 %) (p = 0.31). The mean PDA velocities were higher in the ISS group (2.7 ± 0.4 m/s) and increased at a faster rate than in the no-ISS group at (2.4 ± 0.4 m/s) (p = 0.01). The degree of tricuspid regurgitation, ventricular function, and pulmonary artery band gradients shown by echocardiography were similar in the two groups. The development of ISS after hybrid stage 1 palliation can lead to interstage interventions or earlier comprehensive stage 2 repair. Patients with greater initial weight and a lower stent-to-weight ratio are more likely to develop ISS. The cause of ISS is complex, and additional investigation of its etiology currently is ongoing.

Transcatheter elimination of left-to-right shunts in infants with bronchopulmonary dysplasia is feasible and safe.

OBJECTIVE: To test the hypothesis that transcatheter elimination of left-to-right (L-R) cardiac shunts in former premature infants with bronchopulmonary dysplasia (BPD) is feasible, safe, and is associated with an improvement in respiratory status. DESIGN: Retrospective case review. PATIENTS: Twelve patients with BPD who underwent an attempt at transcatheter closure of an L-R shunt lesion within the first year of life at a single center. Median weight was 5.4 kg and median age was 6 months. Fifteen L-R shunt lesions included patent ductus arteriosus (n = 1), atrial septal defect (ASD) (n = 9), and aortopulmonary collaterals (n = 5). OUTCOME MEASURES: Echocardiographic and clinical markers were collected before and after intervention as well as procedural variables including successful elimination of the shunt and procedural complications. RESULTS: The L-R shunts were successfully occluded in 11/12 (91.6%) patients without any significant procedural adverse event. The ASD closure group demonstrated a decrease in right heart size after the procedure. All patients required respiratory support prior to, and 1 month after, the procedure while only 5/10 (50%) required respiratory support at 12 months of age (P = .0129). There was no change in the median weight percentile over time. CONCLUSION: Transcatheter occlusion of L-R shunts can be performed safely and effectively in children with BPD. Further studies may clarify the role of such therapy in improvement in respiratory physiology over time.

Percutaneous tricuspid valve replacement in congenital and acquired heart disease.

OBJECTIVES: This study sought to describe the first human series of percutaneous tricuspid valve replacements in patients with congenital or acquired tricuspid valve (TV) disease. BACKGROUND: Percutaneous transcatheter heart valve replacement of the ventriculoarterial (aortic, pulmonary) valves is established. Although there are isolated reports of transcatheter atrioventricular heart valve replacement (hybrid and percutaneous), this procedure has been less frequently described; we are aware of no series describing this procedure for TV disease. METHODS: We approached institutions with significant experience with the Melody percutaneous pulmonary valve (Medtronic, Inc., Minneapolis, Minnesota) to collect data where this valve had been implanted in the tricuspid position. Clinical and procedural data were gathered for 15 patients. Indications for intervention included severe hemodynamic compromise and perceived high surgical risk; all had prior TV surgery and significant stenosis and/or regurgitation of a bioprosthetic TV or a right atrium-to-right ventricle conduit. RESULTS: Procedural success was achieved in all 15 patients. In patients with predominantly stenosis, mean tricuspid gradient was reduced from 12.9 to 3.9 mm Hg (p < 0.01). In all patients, tricuspid regurgitation was reduced to mild or none. New York Heart Association functional class improved in 12 patients. The only major procedural complication was of third-degree heart block requiring pacemaker insertion in 1 patient. One patient developed endocarditis 2 months after implant, and 1 patient with pre-procedural multiorgan failure did not improve and died 20 days after the procedure. The remaining patients have well-functioning Melody valves in the TV position a median of 4 months after implantation. CONCLUSIONS: In selected cases, patients with prior TV surgery may be candidates for percutaneous TV replacement.

Use of a dose-dependent follow-up protocol and mechanisms to reduce patients and staff radiation exposure in congenital and structural interventions.

BACKGROUND: Increasingly complex structural/congenital cardiac interventions require efforts at reducing patient/staff radiation exposure. Standard follow-up protocols are often inadequate in detecting all patients that may have sustained radiation burns. METHODS: Single-center retrospective chart review divided into four intervals. Phase 1 (07/07-06/08, 413 procedures (proc)): follow-up based on fluoroscopy time only; frame rate for digital acquisition (DA) 30 fps, and fluoroscopy (FL) 30 fps. Dose-based follow-up was used for phase 2-4. Phase 2 (07/08-08/09, 458 proc): DA: 30 fps, FL: 15 fps. Phase 3 (09/09-06/10, 350 proc): DA: 15-30 fps, FL: 15 fps, use of added radiation protection drape. Phase 4 (07/10-10/10, 89 proc): DA: 15-30 fps, FL: 15 fps, superior noise reduction filter (SNRF) with high-quality fluoro-record capabilities. RESULTS: There was a significant reduction in the median cumulative air kerma between the four study periods (710 mGy vs. 566 mGy vs. 498 mGy vs. 241 mGy, P < 0.001), even though the overall fluoroscopy times remained very similar (25 min vs. 26 min vs. 26 min vs. 23 min, P = 0.957). There was a trend towards lower physician radiation exposure over the four study periods (137 mrem vs. 126 mrem vs. 108 mrem vs. 59 mrem, P = 0.15). Fifteen patients with radiation burns were identified during the study period. When changing to a dose-based follow-up protocol (phase 1 vs. phase 2), there was a significant increase in the incidence of detected radiation burns (0.5% vs. 2%, P = 0.04). CONCLUSIONS: Dose-based follow-up protocols are superior in detecting radiation burns when compared to fluoroscopy time-based protocols. Frame rate reduction of fluoroscopy and cine acquisition and use of modified imaging equipment can achieve a significant reduction to patient/staff exposure.

An institutional approach to interventional strategies for complete vascular occlusions.

Complete vascular occlusions are rare but potentially lethal. Reports on transcatheter therapy are limited to solitary case reports. The study was conducted as a single-center retrospective chart review. Between January 2003 and December 2009, 26 patients underwent cardiac catheterizations for either a known complete thoracic vascular occlusion or for incidental complete vascular occlusion that was noted during cardiac catheterization. Procedural technique, risk factors, and outcomes are reviewed. Median age at the time of diagnosis was 13.3 years (range 2 months to 54 years). In 6 of 26 (23%) patients, the vascular occlusion was of acute onset. Ninety-two percent of patients had at least 1 known risk factor for vascular occlusion, whereas 54% of patients had ≥ 2 risk factors. Successful rehabilitation was achieved in 19 patients, with direct catheter and/or wire manipulation being used to cross the occluded vessel in 15 (75%) patients, radiofrequency (RF) perforation in 3 patients, and perforation with Brockenbrough needle in 1 patient. Subsequent techniques included AngioJet (n = 2), balloon angioplasty and/or stent implantation (n = 18), and adjuvant local administration of recombinant tissue-plasminogen activator (n = 3). Reinterventions were required in 5 patients, and 8 patients died during the study period from causes unrelated to the catheterization procedure(s). Median follow-up of patients after successful recanalization was 12.6 months (range 1 day to 64 months), and the median duration of survival free from reintervention was 11.8 months (range 1 day to 64 months). In most patients, risk factors can be identified that are associated with the occurrence of a complete vascular occlusion. Different treatment strategies are used in patients having chronic compared with acute occlusions. Residual vascular lesions (hypoplasia or stenosis) are often associated with occurrence of reobstructions and should therefore be treated to prevent such an occurrence. Postprocedural anticoagulation is important in maintaining vascular patency.

Histopathologic evaluation of patent ductus arteriosus stents after hybrid stage I palliation.

The aim of this study was to determine the histopathology of patent ductus arteriosus (PDA) in-stent stenosis after hybrid stage I palliation. The hybrid approach to palliation of hypoplastic left heart syndrome can be complicated by the development of in-stent stenosis of the PDA. This may obstruct retrograde aortic arch flow, decrease systemic circulation, and lead to interstage interventional procedures. Stented PDA samples removed from eight patients undergoing comprehensive stage II repair were examined by way of radiography and histochemistry (hematoxylin and eosin, Movat pentachrome, α-smooth muscle actin, and proliferating cell nuclear antigen). A retrospective chart review of the patients was also performed. PDA stents were in place in the PDA for a mean period of 169 ± 28 days in patients who had a mean age of 176 ± 30 days at the time of stent removal. Stent deployment caused chronic inflammation, caused fibrin deposition, and induced vascular smooth muscle-cell (VSMC) proliferation in the area immediately surrounding the stent struts. The neointimal region was composed largely of smooth muscle cells that appeared to be fully differentiated by the lack of PCNA staining. Neointimal thickening occurs in the PDA after stent placement for hybrid palliation of HLHS and is the result of inflammation, extracellular matrix deposition, and smooth muscle-cell proliferation in the peristrut region. This finding suggests that proliferating VSMCs in the peristrut region may provide the impetus for inward neointimal formation and therefore the manifestation of in-stent stenosis.

Predictors of retrograde aortic arch obstruction after hybrid palliation of hypoplastic left heart syndrome.

A potential complication after hybrid stage 1 palliation for hypoplastic left heart syndrome (HLHS) is retrograde aortic arch obstruction (RAAO). This can lead to increased morbidity and unplanned surgical or interventional procedures in the interstage period. This study aimed to identify potential predictors of RAAO by analyzing initial echocardiograms and angiograms before hybrid stage 1 palliation. For this study, 96 patients who underwent hybrid stage 1 palliation between July 2002 and July 2009 were reviewed, 68 of which had standard HLHS and met the inclusion criteria. The initial echocardiogram, hybrid stage 1 angiograms, and follow-up echocardiograms were reviewed. Anatomic and hemodynamic measurements were obtained by both modalities, and comparisons were made between those who developed RAAO and those who did not. Of the 68 patients, 20 (29%) had RAAO. The mean aortic root size was smaller for the patients who had RAAO (3.6 vs 4.4 mm; p = 0.036). The angiographic angle between the aortic isthmus and the patent ductus arteriosus (PDA) was significantly larger in the RAAO group (86° vs 63°; p = 0.008). The retrograde aortic arch velocities were higher in the RAAO group. Patients with RAAO have a smaller aortic root and higher retrograde velocities on initial echocardiogram. Patients with RAAO show a larger angle between the retrograde arch and PDA on angiogram. Because RAAO is an important potential complication after hybrid stage 1 palliation for HLHS, identification of predictors of RAAO may lead to improved care and outcome for patients with RAAO.

Quality outcomes of ACHD patients undergoing cardiovascular procedures and hospital admissions in a free-standing children's hospital.

OBJECTIVES: Describe quality outcomes of adults with congenital heart disease (ACHD) undergoing cardiovascular procedures and admissions in a free-standing children's hospital with a multi-disciplinary ACHD program and compared with pediatric outcomes. BACKGROUND: A challenge for the U.S. healthcare system is where to treat the >1 million ACHD patients (pts): adult hospitals without CHD care, or pediatric hospitals without adult services. METHODS: We reviewed all CHD pts ≥ 18 yrs of age from 2002-2007. Procedural and hospital related morbidity and mortality were recorded. ANOVA and t-test compared adult with pediatric pts. RESULTS: Overall, 782 pts, mean age of 29.8 ± 9.9 yrs, encountered 1490 procedures/admissions. For 178 cardiac surgeries (72% reoperations), mortality was 1.8% and complication rate was 7.3%. There was 0% mortality for 412 cardiac catheterizations, 311 electrophysiological procedures, 401 transesophageal echocardiograms (TEE), 244 exercise tests (ETT) and 54 medical admissions. Major adverse event rate was 0.6% for cardiac catheterization and electrophysiological procedures. No adverse events occurred during TEE and ETT. Only 4 pts required transfer to an adult institution (0.25%). There was no significant difference in mortality or adverse events between pediatric and adult CHD pts, p>0.05. CONCLUSIONS: The optimal setting to provide ACHD care remains a complex issue. Our study is the first to demonstrate 1) a low incidence of morbidity and mortality for ACHD pts undergoing cardiovascular procedures or admissions at a free-standing children's hospital, 2) outcomes comparable to pediatric CHD pts. Future models incorporating ACHD programs within pediatric heart centers should be considered to care for this complex population.

Radiation protection during hybrid procedures: innovation creates new challenges.

BACKGROUND: The cooperation between interventional cardiologists and cardiothoracic surgeons has expanded the spectrum of treatment modalities for patients with congenital heart disease. These hybrid techniques have created new challenges, one of which being the provision of adequate but practical radiation protection. This study evaluates the use of a lightweight radiation protection drape (RADPAD) that may be suitable for shielding during hybrid procedures. METHODS: To simulate a pediatric patient, an 8.7 liter water-filled tub was placed on an X-ray table and exposed to 10-second cine acquisition runs. Radiation exposure was measured at twelve specified locations around the table using a model with three different levels of radiation protection: no shielding, shielding using a traditional 0.35 mm lead-equivalent apron, and shielding using the 0.25 mm lead-equivalent RADPAD. RESULTS: The traditional lead apron and the RADPAD significantly reduced the amount of radiation dose when compared with no shielding. The standard lead apron provided slightly greater radiation protection than the RADPAD (0.000064 radiation absorbed dose [rad] vs. 0.000091 rad; p = 0.012). The measured rad was significantly higher on the right side of the table, and the measured radiation dose decreased significantly with increasing distance from the table. CONCLUSIONS: The RADPAD has been shown to function as an efficient shielding device, even though it does not quite match the protection that can be expected from a standard lead apron. It complies with regulatory radiation protection requirements and its lightweight and sterile use make it particularly useful during hybrid procedures in the operating room.

Completion angiography after cardiac surgery for congenital heart disease: complementing the intraoperative imaging modalities.

Residual structural pathology after cardiac surgery for congenital heart disease may complicate postoperative recovery. Completion angiograms obtained in the operating room may facilitate early detection and therapy of residual structural abnormalities. Our objective here is to report our institutional experience performing completion angiograms after cardiopulmonary bypass surgery. Between October 2007 and August 2008, 31 patients underwent completion angiograms after 32 cardiac surgical procedures. The median age was 7.5 months (range, 50 days to 31.2 years) and the median weight was 6.5 kg (range, 3.1-153 kg). Type of procedure, angiographic findings, and therapeutic decision were retrospectively reviewed. Procedures (proc) evaluated through completion angiography included comprehensive stage II or Glenn (n = 13), aortic arch reconstruction/conduit (n = 3), repair/palliation of tetralogy of Fallot or pulmonary atresia with ventricular septal defect (n = 4), PVR or conduit replacement (n = 5), and others (n = 7). Unexpected pathology was identified in 18 of 32 (56.3%) proc, which included left pulmonary artery (LPA) stenoses (n = 15), right pulmonary artery (RPA) stenoses (n = 11), and stenosis impairing coronary blood flow (after DKS; n = 1). In 9 of 32 (28.1%) proc, findings may have led to a change in therapeutic management. This included surgical revision (n = 1), 'Hybrid' therapy in the same setting (n = 2: LPA stent, 1; RPA balloon, 1), early catheterization within 3 months (n = 4), and change in medical management (n = 2: change in anticoagulation, 1; early CT, 1). Complications related to completion angiography were seen in only a single procedure (LPA staining). In conclusion, completion angiograms using a dedicated Hybrid cardiac operating suite may aid in early diagnosis and therapy of postsurgical abnormalities. They complement other methods of intraoperative imaging and may reduce the potential need for early surgical or transcatheter reintervention.

An animal model for hybrid stage I palliation of hypoplastic left heart syndrome.

Hybrid palliation has evolved as an important alternative treatment strategy for patients with hypoplastic left heart syndrome (HLHS). The procedural cooperation between cardiothoracic surgeon and interventional cardiologist is not intuitive and there is an increasing demand to avoid mistakes of the 'early learning curve,' through in vivo teaching using an animal model. We describe a unique experience of developing a piglet model that can be used to teach the procedural technique of hybrid Stage I palliation. The model has been used in about 140 piglets and consists of percutaneous patent ductus arteriosus (PDA) balloon angioplasty using a 6-mm balloon in piglets with a weight of 2-2.5 kg, followed within 4-7 days by bilateral PA banding as well as PDA stent placement in a hybrid procedure through a midline sternotomy.

Treatment of aortic arch aneurysm with a NuMED-covered stent and restoration of flow to excluded left subclavian artery: perforation and dilation of e-PTFE can be done!

We describe a case using a NuMED-covered Cheatham-Platinum (CP) stent (NuMED, Hopkinton, NY) to treat an aneurysm after previous balloon angioplasty and bare stent implantation for coarctation of the aorta (CoA). Exclusion of the left subclavian artery (LSCA) was anticipated. After wire perforation of the covered CP stent, balloon angioplasty was performed through a stent cell to recannulize the LSCA.

"Hybrid" stent delivery in the pulmonary circulation.

OBJECTIVE: We sought to describe our institutional experience providing "hybrid" intraoperative stent therapy for pulmonary artery (PA) stenoses. BACKGROUND: Surgical patch angioplasty, transcatheter stent therapy and intraoperative stent delivery are valuable treatment options for PA stenoses. The experience with intraoperative hybrid therapy has increased and new techniques and equipment have become available. METHODS: This study involves a retrospective review of 20 patients with a median age of 5.1 years who underwent hybrid PA stent therapy between March 2003 and April 2008. Thirteen patients had underlying diagnoses of either tetralogy of Fallot, pulmonary atresia with a ventricular septal defect (VSD) or truncus arteriosus. RESULTS: In 15 procedures, stents were implanted under direct vision. In 3 procedures, stents were implanted using vascular puncture with angiographic guidance, and in 2 procedures, stents were implanted using a combination of direct vision and fluoroscopy/angiography. Successful stent deployment was achieved in 18/20 (90%) procedures. One stent was malpositioned from the right ventricular outflow tract through a VSD, while another stent fractured as a result of high-pressure balloon expansion of a very resistant lesion. Adverse events were encountered in 3/20 (15%) procedures, which included the 2 "unsuccessful" stent deliveries. The median follow up thus far has been 1.7 years (41 days to 5.1 years). Seven of 20 (35%) patients required repeated interventions at the site of previous stent placement at a median interval of 8.5 months. CONCLUSIONS: Hybrid stent delivery in the operating room, using either direct vision or vascular puncture, is safe and effective. Using a well-equipped hybrid operating suite facilitates safe intraoperative stent delivery in a wide variety of patients. Close cooperation between the surgical and interventional teams is essential.

Interstage echocardiographic changes in patients undergoing hybrid stage I palliation for hypoplastic left heart syndrome.

OBJECTIVE: The hybrid procedure is an alternative for initial palliation for patients with hypoplastic left heart syndrome. No echocardiographic data exist for the interstage (IS) period. The goal of this study was to describe the echocardiographic changes during this period. METHODS: A chart review was performed on patients discharged from the hospital with the diagnosis of hypoplastic left heart syndrome who underwent hybrid palliation. Echocardiograms at hospital discharge (post-hybrid), before and after any IS interventions, and before comprehensive stage II procedure were reviewed. Distal right pulmonary artery (RPA) and left pulmonary artery (LPA) velocity, slope, velocity time integral (VTI), pressure halftime (p1/2), pulsatility index (PI), and systolic/diastolic (S/D) ratio of the waveforms were recorded. Atrial septal defect (ASD) mean gradient, ductus arteriosus peak velocity, retro-aortic arch peak velocity, tricuspid regurgitation (TR), and right ventricular function were documented. Exploratory hypotheses were tested with chi-square and t tests. Stepwise logistic regression was used to identify any multiple sets of relatively independent variables. RESULTS: Thirty patients met inclusion criteria. Fourteen patients underwent 22 different interventions at the atrial septum, ductus arteriosus, or retro-aortic arch in the IS period. Baseline ASD gradient (P = .012) and ductus arteriosus velocity (P = .002) predicted an IS intervention. There were significant differences in LPA and RPA VTI (P = .011, .03), p1/2 (P = .038, .008), and S/D (P = .012, .033); RPA slope (P = .013); ASD gradient (P = .003); ductus arteriosus velocity (P = .021); and TR (P = .031) before and after an intervention. There were significant differences in post-hybrid versus pre-comprehensive stage II LPA and RPA VTI (P = .009, .022), PI (P = .031, .022), and peak velocity (P = .004, .037); RPA S/D (P = .025) and p1/2 (P = .029); ductus arteriosus velocity (P < .001); retro-aortic arch peak velocity (P = .035); and ASD mean gradient (P < .001). Pre-comprehensive stage II function tended to predict death (P = .085). CONCLUSION: Echocardiographic parameters help predict IS course and guide clinical therapy for this patient population.

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.

Usefulness of multidetector CT imaging to assess vascular stents in children with congenital heart disease: an in vivo and in vitro study.

OBJECTIVE: To evaluate varying CT settings to visualize pediatric vascular stents in comparison to digital angiography (DA). BACKGROUND: There is a great clinical interest in substituting noninvasive methods to follow up children with congenital heart disease after interventional treatment. MATERIALS AND METHODS: CT studies in small children with transcatheter placed stents were reviewed, retrospectively. Furthermore, eight stents were implanted in tubes and partially obstructed. CT exams were performed on varying scanners (4 up to 64 slices) with corresponding tube settings. The effects of dose on image quality were evaluated regarding stent size, strut thickness, and in-stent stenoses in comparison to DA. RESULTS: Fourteen children with 28 implanted stents were identified. Significant differences between higher and lower radiation settings were not found, corresponding with the phantom, where moderate tube setting showed the best results. In vitro, there was an improvement with increasing number of detector rows, which resulted in a decrease of stent strut overestimation (295% down to 201%; P < 0.0001) and a better agreement with DA measurements for mild (78% up to 91%; P = 0.003) and moderate in-stent stenoses (80% up to 99%; P = 0.0001). CONCLUSION: Higher radiation exposure settings did not improve image quality, suggesting that the exams could be performed at a lower radiation dose.

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.

CT of pediatric vascular stents used to treat congenital heart disease.

OBJECTIVE: The purpose of our study was to assess the visibility of lumen narrowing of pediatric vascular stents using various CT dose parameters in an in vitro model. MATERIALS AND METHODS: Ten steel stents of varying designs and sizes commonly used in the treatment of congenital heart disease were implanted in polyvinyl chloride (PVC) tubes and three of the 10 stents were partially obstructed with wax by filling 25% (mild) to 60% (moderate) of the lumen with contrast material. On a 64-MDCT scanner, the stents were scanned at tube voltages (kVp) of 80, 100, and 120 and at tube currents (mA) of 40, 80, 120, and 160. CT measurements of inner-stent diameter, strut thickness, and percent lumen (in-stent) stenoses were compared with biplane fluoroscopy of digital angiography. RESULTS: The stent diameter and percent stenosis on all CT images were consistently smaller than measured on digital angiography but were highly correlated (r = 0.97; p < 0.0001) with improvement as stent diameter increased (93% agreement with digital angiography for 4-mm stent, up to 99% for 25-mm stent; p = 0.001). Moderate stenosis could be assessed better than mild stenosis (99% vs 91% agreement with digital angiography; p = 0.003). Increasing exposure settings improved CT correlation of all measurements for mA up to 120 and kVp up to 100 (98.1% agreement). Higher settings did not improve accuracy (93.9% for 160 mA at 120 kVp; p = 0.03). CONCLUSION: CT is feasible to assess lumen narrowing of pediatric vascular stents at a wide range of tube settings. The study suggests that it is possible to lower the radiation exposure settings without loss in image quality or accuracy in detecting in-stent stenoses.

Stenting complex aortic arch obstructions.

OBJECTIVE: To present our institutional experience of endovascular stent therapy in patients with complex aortic arch lesions. BACKGROUND: The management of aortic arch obstructions is complex and many physicians are either reluctant to treat mild-moderate aortic arch lesions associated with systemic hypertension or instead refer to high-risk surgical alternatives. Reported data on transcatheter stent therapy of complex aortic arch lesions are scarce. METHODS: Between October 2002 and November 2006, 40patients (pts) had complex aortic arch lesions treated with stent implantation in 42 procedures (proc). Aortic arch hypoplasia was present in 30/42 proc (71.4%). The median age was 10 year (16 days - 37 years). In 40/42 proc (95.2%) patients had previous transcatheter or surgical aortic arch interventions. RESULTS: Procedural success in achieving a peak systolic gradient reduction to or=90% of the "normal" adjacent aortic arch was achieved in 38/42 proc (90.5%). The diameter of the arch obstruction increased from a median of 7.55 mm to a median of 14 mm (P < 0.0001) and the peak systolic gradient was reduced from a median of 23 mm Hg to a median of 2 mm Hg (P < 0.0001). Arch vessels were crossed in 31/42 proc (73.8%). Periprocedural adverse events were encountered in 13/42 proc (30.9%), predominately in patients with a weight below 10 kg or univentricular physiology. The median follow-up was 1 year (32 days - 3.8 years). The incidence of systemic hypertension was significantly reduced from 22/42 (52.4%) before the procedure to 6/39 (15.4%) at the most recent follow-up (P = 0.0005). CT or MRI evaluations were performed in 18 pts, documenting all crossed arch vessels to appear patent. CONCLUSIONS: Stenting of complex aortic arch lesions can be performed safely and effectively with excellent, immediate, and midterm results. Patients with a weight below 10 kg or after Hybrid stage I palliation are at increased risk of adverse events. Stents can be placed across major arch vessels without compromising distal perfusion in otherwise normal vasculature.

Palliation via hybrid procedure of a 1.4-kg patient with a hypoplastic left heart.

Despite improvements in survival of patients with hypoplastic left heart syndrome (HLHS) with various palliative procedures, certain risk factors, such as weight less than 2.5 kg, continue to predict increased mortality. We report the palliation of a patient with HLHS weighing 1.4 kg via a hybrid procedure consisting of banding of the pulmonary arteries bilaterally, stenting the ductus arteriosus, and balloon atrial septostomy. We propose that this may be another alternative for palliation in this high-risk patient group.