Percutaneous Balloon-Expandable Stent Implantation to Treat Transverse Aortic Arch Obstruction: Medium- to Long-Term Outcomes of a Retrospective Multicenter Study.

BACKGROUND: Transverse aortic arch obstruction is a challenging lesion for which stent implantation provides a potentially important alternate therapy. The objectives were to evaluate the technical, procedural, and medium-to-long-term clinical outcomes of percutaneous stent implantation of transverse aortic arch obstruction. METHODS: This is a retrospective, multicenter study of transverse aortic arch stent implantation. Univariable and multivariable analyses were performed. RESULTS: Index catheterization included 187 stent implants in 146 patients. The median age is 14.3 years (interquartile range, 9.3-19), weight is 53 kg (30-69), and follow-up is 53 months (12-120). The most common stent design was open cell (n=90, 48%). Stents overlapped 142 arch vessels (37 carotid arteries) in 118 (81%) cases. Technical and procedural success rates were 100% and 88%, respectively. Lower weight (P=0.018), body surface area (P=0.013), and minimum-to-descending aortic diameter ratio (P<0.001) were associated with higher baseline aortic gradient. The residual gradient was inversely associated with implant and final dilation diameters (P<0.001). The combined incidence of aortic injury and stent-related complications was 14%. There were no reports of abnormal brain scans or stroke. Blood pressure cuff gradient, echocardiographic arch velocity, and hypertension rates improved within 1-year follow-up with increased antihypertensive medication use. Reintervention was reported in 60 (41%) patients at a median of 84 (22-148) months to first reintervention. On multivariable logistic regression, residual aortic gradient >10 mm Hg was associated with increased odds of reintervention at all time points when controlling for each final dilation diameter, weight, and minimum-to-descending aortic diameter ratio. CONCLUSIONS: Transverse aortic arch stent implantation has high rates of technical, procedural, and medium-to-long-term clinical success. Aortic gradient >10 mm Hg is associated with increased odds of reintervention at 1-year and most recent follow-ups. Open cell stent design was frequently used for its advantages in conformability, perfusion of arch vessels, low fracture rate, and the ability to perform effective angioplasty of side cells.

Implantable pulmonary artery pressure monitoring device in patients with palliated congenital heart disease: Technical considerations and procedural outcomes.

OBJECTIVE: We describe the technical considerations of transcatheter implantation of the CardioMEMS™ HF System (Abbott, Abbott Park, IL) in adult patients with complex palliated congenital heart disease (CHD) and advanced heart failure (HF). BACKGROUND: Ambulatory pulmonary artery (PA) pressure monitoring with implantable hemodynamic monitors (IHMs) has been shown to reduce HF-related hospital admissions in non-CHD populations. HF is a common late cardiovascular complication in adult CHD necessitating better understanding of IHM application in this population. METHODS: We analyzed adults with complex CHD and advanced HF who were referred for CardioMEMS™ device implantation (2015-2018). Feasibility of device implantation, defined by successful device implantation and calibration, and procedural outcomes were evaluated. RESULTS: CardioMEMS™ was successfully implanted in all 14 adults (35.5 ± 9.2 years old, 72 ± 12 kg) with complex CHD (single ventricle/Fontan, n = 8 [57%]; d-transposition of the great arteries/atrial switch, n = 6 [43%]). The device was delivered via femoral venous access in 13 (93%) patients and implanted in the left PA in 12 (86%). A long sheath was used in 8 (57%) patients, including 5/6 with an atrial switch operation. There was one device migration that did not require retrieval. CONCLUSIONS: Transcatheter implantation of an IHM is feasible in select complex adult CHD patients with advanced HF. Further studies evaluating integration of ambulatory hemodynamics and the impact on clinical care are needed. This technology has the potential to improve medical management of advanced HF in patients with Fontan and atrial switch physiologies and provide new insights into their ambulatory hemodynamics.

Leaflet morphology classification of the Melody Transcatheter Pulmonary Valve.

OBJECTIVE: We sought to describe the leaflet morphology variation in the Melody Transcatheter Pulmonary Valve (TPV) and evaluate associated outcomes. The Melody TPV is constructed from harvested bovine jugular venous valves which have been rigorously tested. Natural anatomic leaflet variations are seen in the Melody TPV but have not been evaluated. DESIGN: A Melody TPV leaflet morphology classification system was devised after reviewing a subset of photographed and implanted TPVs. All images were blindly reviewed by implanters and classified. Midterm hemodynamic outcomes and complications of the Melody TPVs were compared by leaflet morphology. RESULTS: Photographed Melody TPVs implanted between 2011 and 2016 (n = 62) were categorized into the following leaflet morphology types: A-symmetric trileaflet (47%); B-asymmetric trileaflet with a single small leaflet (32%); C-asymmetric trileaflet with a single large leaflet (16%); D-rudimentary leaflet with near bicuspid appearance (5%). Acceptable hemodynamic function at 6 months postimplantation was seen in 97.5% of valves. Over a median follow-up of 1.5 years (range 0-4.4 years), two TPVs (Type A) had > mild regurgitation. Nine TPVs developed complications (endocarditis, 3; stent fracture, 2; refractory arrhythmia, 1; conduit replacement, 2; death, 1), of which 6 required reintervention. There was no significant difference in outcomes based on Melody TPV leaflet morphology type. CONCLUSIONS: The Melody TPV can be classified into one of four categories based on leaflet morphology. Study outcomes were not associated with leaflet morphology. Further documentation and evaluation of Melody TPV morphology may lead to better understanding of this technology.

Cerebral Blood Flow Following Hybrid Stage I Palliation in Infants with Hypoplastic Left Heart Syndrome.

Hypoplastic left heart syndrome (HLHS) palliation may result in altered cerebral blood flow with subsequent neurodevelopmental implications. The purpose of the study was to assess blood flow in the middle cerebral artery (MCA) and investigate the relationship with early neurodevelopmental outcomes in infants with HLHS after hybrid stage I. Transcranial Doppler (TCD) was performed to obtain peak systolic, end-diastolic, and mean velocities, as well as pulsatility index of the MCA in infants with HLHS (n = 18) at baseline and at 2, 4, and 6 months of age. Developmental assessment was performed at 6 months of age. Results of TCD and development were compared to healthy control subjects (n = 6) and normative data. Overall, peak systolic velocity (p = 0.0031), end-diastolic velocity (p < 0.0001), and mean velocity (p < 0.0001) were significantly lower and pulsatility index (p = 0.0011) significantly higher in the HLHS group compared to the control group. A significant increase in change over time was noted for peak systolic velocity (p < 0.0016) and mean velocity (p < 0.0046). There was no significant correlation between TCD variables and development scores. TCD values in 5-6 months old infants with HLHS who undergo hybrid stage I palliation had consistently lower blood flow velocities than control infants; however, pulsatility index was slightly higher. No correlation between TCD measurements and measures of cognitive, language, and motor skills were noted.

Intravascular Ultrasound Characterization of a Tissue-Engineered Vascular Graft in an Ovine Model.

Patients who undergo implantation of a tissue-engineered vascular graft (TEVG) for congenital cardiac anomalies are monitored with echocardiography, followed by magnetic resonance imaging or angiography when indicated. While these methods provide data regarding the lumen, minimal information regarding neotissue formation is obtained. Intravascular ultrasound (IVUS) has previously been used in a variety of conditions to evaluate the vessel wall. The purpose of this study was to evaluate the utility of IVUS for evaluation of TEVGs in our ovine model. Eight sheep underwent implantation of TEVGs either unseeded or seeded with bone marrow-derived mononuclear cells. Angiography, IVUS, and histology were directly compared. Endothelium, tunica media, and graft were identifiable on IVUS and histology at multiple time points. There was strong agreement between IVUS and angiography for evaluation of luminal diameter. IVUS offers a valuable tool to evaluate the changes within TEVGs, and clinical translation of this application is warranted.

Accuracy of Imaging Modalities in Detection of Baffle Leaks in Patients Following Atrial Switch Operation.

AIMS: Patients with dextro-transposition of the great arteries (d-TGA) status post atrial switch operation are vulnerable to complications such as baffle leaks. The best noninvasive imaging modality to detect baffle leaks is unknown. The purpose of this study was to determine the sensitivity and specificity of different noninvasive imaging modalities in the detection of baffle leaks in this population. METHODS AND RESULTS: A single center retrospective chart review of atrial switch patients was performed. Sensitivity, specificity, negative predictive value, and positive predictive value for detecting leaks were calculated for transthoracic echocardiogram (TTE) with and without agitated saline, transesophageal echocardiogram (TEE) with and without agitated saline, and cardiac magnetic resonance imaging (cMRI). Studies were included if performed within 1 year of catheterization. Angiography via catheterization was used as the gold standard for the detection of baffle leaks. Fifty-eight atrial switch patients (54 Mustards: four Sennings) from a single pediatric center, undergoing 76 catheterizations, were analyzed. Thirty-nine catheterizations documented a baffle leak. Overall combination of sensitivity and specificity was better in agitated saline studies (TTE: sensitivity 71.4%, specificity 100%; TEE: sensitivity 100%, specificity 92.3%) versus nonagitated studies (TTE: sensitivity 50.0%, specificity 100%; TEE: sensitivity 83.3%, specificity 77.8%; or cMRI: sensitivity 66.7%, specificity 100%). CONCLUSION: TTE or TEE with agitated saline is superior to cardiac magnetic resonance imaging or nonagitated saline TTE and TEE in detecting baffle leaks in atrial switch patients. Agitated saline studies should be performed in this population when looking for baffle leaks.

Early results of neurodevelopment following hybrid stage I for hypoplastic left heart syndrome.

Motor skills and neurodevelopment in infants with hypoplastic left heart syndrome (HLHS) who have undergone Hybrid Stage I palliation is unknown. The purpose of this study is to assess early neurodevelopment in infants with HLHS after Hybrid Stage I palliation. Developmental assessment was performed in HLHS infants who underwent Hybrid Stage I palliation at 2 and 4 months of age using the Test of Infant Motor Performance, and at 6 months of age, prior to undergoing the second staged surgery, using the Bayley Scales of Infant and Toddler Development, 3rd edition (Bayley-III). Results were compared to healthy control subjects and norm-referenced data. The HLHS group scored between -1 and -2 standard deviations (SD) below the mean at 2 months of age (p = 0.002), and within -1 SD of the mean, at 4 months of age (p = 0.0019), on the TIMP. Compared to the control group, composite motor skills were significantly lower at 6 months of age on the Bayley-III in the HLHS group (p = 0.0489), however, not significant for cognitive (p = 0.29) or language (p = 0.68). Percentile rank motor scores were 17 ± 20 % in the HLHS group compared to 85 ± 12 % for the healthy age-matched control group. Infants with HLHS who undergo Hybrid Stage I palliation score lower on standardized motor skill tests compared to healthy age-matched controls and the norm-referenced population. This suggests that infants with HLHS have poorer motor skill performance than typically developing infants at 6 months of age.

Device closure of secundum atrial septal defects in infants weighing less than 8 kg.

This study aimed to assess the technical aspects of atrial septal defect (ASD) closure using the Amplatzer septal occluder (ASO) and the Gore Helex septal occluder (GHSO) for infants weighing less than 8 kg and to determine the safety, effectiveness, and near-to-intermediate-term outcome of the closure. The Mid-Atlantic Group of Interventional Cardiology Registry of percutaneous, transcatheter ASD closure procedures was reviewed for this analysis. Patients from 10 hospitals in the United States were included. The cohort for this report consisted of 68 patients weighing less than 8 kg (range, 2.3-7.8 kg; mean, 5.5 ± 1.6 kg) and ranging in age from 1 to 24 months (mean, 8.6 ± 4.7 months). The indications for ASD closure were failure to thrive, significant right heart enlargement, shunts otherwise thought to be hemodynamically significant, and poor overall clinical status. Devices were successfully implanted in 66 of the 68 infants (97.1 % procedural success rate). Five minor procedure-related complications occurred. At follow-up assessment, clinical status had improved significantly as measured by improved weight gain and decreased ventilator or oxygen dependence. All residual shunts spontaneously closed during the follow-up period. Six late deaths occurred, none of which were clearly device related. The ASO and GHSO can be safely and effectively implanted for ASD closure in infants weighing less than 8 kg. These procedures usually are successful and seldom complicated, resulting in significant clinical improvement.

The Medtronic Melody® transcatheter pulmonary valve implanted at 24-mm diameter--it works.

OBJECTIVES: We report the Melody valve implanted and/or expanded to 24-mm diameter. BACKGROUND: The Medtronic Melody valve has been implanted up to 22 mm in the pulmonary position for over a decade. METHODS: A retrospective chart review was performed on 82 patients who underwent Melody valve implant. Technical implant method, pre- and postimplant echocardiographic findings, and initial follow-up were reviewed. RESULTS: Between 04/2008 and 12/2011, 13 Melody valves were successfully implanted in 11 patients, median age 35 years (range 16-61 years), in the pulmonary (bioprosthetic valve, right ventricle to pulmonary artery conduit, native valve) position (n = 9), tricuspid position (bioprosthetic valve n = 3), and aortic position (bioprosthetic valve n = 1). Ten valves were delivered on a 24-mm balloon in balloon catheter and three were implanted using a 22-mm Ensemble balloon delivery system, followed by postdilation using a 24-mm × 2-cm Atlas balloon catheter. Postimplant, the median peak systolic gradient across the pulmonary valve was 7 mm Hg and median gradient across the tricuspid valve was 3 mm Hg. There was no change in gradient across the Melody valve in the aortic position where valve prosthesis-patient mismatch was present. Postimplant intracardiac echocardiography demonstrated none or mild valve regurgitation. No more than mild regurgitation was noted at a median follow-up of 9.5 months. CONCLUSIONS: The Melody valve can be implanted at 24 mm in the stenotic/regurgitant bioprosthetic pulmonary, tricuspid, and aortic valve, dysfunctional right ventricle to pulmonary artery conduit, and the native right ventricular outflow tract, whereas the valve remains competent with only mild regurgitation.

Strain echocardiographic assessment of ventricular function after percutaneous pulmonary valve implantation.

INTRODUCTION: Percutaneous pulmonary valve implantation (PPVI) is an emerging therapy for pulmonary valve dysfunction. Minimal data on the midterm effects of PPVI on ventricular function exist. We describe the effects of PPVI on right and left ventricular (RV, LV) function with speckle tracking echocardiography. METHODS: Patients who met the inclusion criteria of the Food and Drug Administration Phase 1 Feasibility Clinical Trial PPVI were identified. Patients were studied with echocardiograms at baseline, post-PPVI (day of discharge), 3 months, and at 6 months. Patients were studied by cardiac magnetic resonance at baseline and at 6 months. Longitudinal strain was measured at the basal, mid, and apical portions of the RV, interventricular septum (IVS), and LV. Global RV and LV strain and strain rates were recorded. Paired t-tests were used for analysis. RESULTS: Ten patients were analyzed: nine patients were a variant of tetralogy of Fallot and one patient had complex LV outflow obstruction requiring a Ross and RV-pulmonary atresia conduit. Mean age was 24.4 ± 7.6 years. Indication for PPVI was pulmonary regurgitation in six patients, stenosis in two patients, and stenosis/regurgitation in two patients. After PPVI, both RV systolic pressure and RV to pulmonary artery pressure gradient significantly decreased. Cardiac magnetic resonance RV end-diastolic volume significantly decreased. IVS-mid, IVS-apical, and LV-global strain significantly increased and RV-basal decreased immediately after PPVI. Global RV a' strain rate significantly increased immediately after PPVI. However, RV, IVS, and LV strain/strain rate values between baseline and the 6 month echocardiographic study were either similar or significantly decreased. CONCLUSION: Despite improvement in RV hemodynamics, there was a decrease or no improvement in RV and LV function as measured by strain echocardiographic values at midterm follow-up. Larger studies with longer follow-up are needed to determine if these results remain consistent.

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.

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.

"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.

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.

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.

Assessment of in-stent stenosis in small children with congenital heart disease using multi-detector computed tomography: a validation study.

OBJECTIVES: Our purpose was to investigate the diagnostic reliability of multi-detector computed tomography (MDCT) in assessing in-stent stenosis compared to digital angiography (DA) in small children. BACKGROUND: Little is known about the feasibility of using MDCT to assess stents placed to treat children with congenital heart disease (CHD). METHODS: Twenty-two children (median age [range], 2(3/4) [(1/2) to 12] years) with 42 transcatheter placed stents (median diameter: 7.2 [3.4-16.3] mm) in the pulmonary arteries (n = 36), aorta (2), PDA (1), and SVC (3) underwent both MDCT and DA due to suspected hemodynamic problems. RESULTS: Independent "blinded" observers were able to measure stent and minimal luminal diameters in 115 out of 124 (93%) stent segments on MDCT and DA. The interobserver variability was low (mean difference: 0.5, SD 0.8 mm) with high correlation (r = 0.97; P < .0001). The percent stenosis by MDCT correlated well with DA (r = 0.89, P < .0001; mean error 2.7, SD 10.4%). For all grades of stenosis, the sensitivity and specificity for MDCT were 58% and 97%, respectively. At a threshold of approximately > or =20% stenosis sensitivity became >98%. All stent associated complications [fracture (4), vascular narrowings (11)] were diagnosed by MDCT. As the stent diameter increased, there was significantly reduced variability between MDCT and DA for in-stent stenosis (P < .0001). CONCLUSION: In small children, MDCT is a feasible and promising method for assessing stent associated complications in the treatment of CHD. Cardiac surgeons and interventional cardiologists might rely on this imaging modality to plan specific interventions more precisely and to assess the results upon follow up.