Stent expansion of restrictive Fontan conduits to nominal diameter and beyond.

BACKGROUND: Mechanical factors may cause bottlenecks in a Fontan circuit. Extracardiac conduits (ECC) are placed at a young age, but the materials do not allow growth. Restriction in ECC dimensions may deteriorate the function of the circuit. AIMS: This study aimed to evaluate the feasibility and safety of stent expansion of an ECC to the nominal dimension at the time of implant and, if possible, beyond nominal. METHODS: Retrospective, single-center observational review of all ECC Fontan patients who received a stent to expand a previously placed surgical conduit. RESULTS: A total of 44 restrictive conduits were stented over a 14-year study period with a median of 11.8 (interquartile ranges [IQR]: 9.1-13.8) years after ECC placement. Cross-sectional areas were a median of 30% (IQR: 21-42) smaller than the originally placed ECC; there was no gradient in 23/44 patients and in 21/44, a minimal gradient of 1.3 ± 0.5 (range 1-3 mmHg). All conduits could be enlarged with a significant (p < 0.0001) increase in diameter from 13.6 ± 1.8 to 19.2 ± 1.2 mm, corresponding to a median cross-sectional area increase of 171% (IQR: 153-220). In three patients where the conduits were not contracted, expansion of between 127% and 165% was obtained. There were no conduit ruptures and only one minor complication. CONCLUSIONS: ECC in some Fontan patients become smaller than nominal over time, usually without overt symptoms. The dimensions of ECC's can be safely and significantly increased to nominal or even beyond employing stenting. It allows adjustment of ECC dimensions to compensate for somatic growth.

Can ductus arteriosus morphology influence technique/outcome of stent treatment?

INTRODUCTION: Results and outcomes of ductus arteriosus stenting vary widely. The aim of this study was to determine whether ductus morphology is associated with different procedural outcome. METHODS: Over an 18-year period, 123 patients presented with ductal dependent pulmonary blood flow. Results were retrospectively assessed based on radiographic anatomic features of the ductus arteriosus: Group 1: "straight" ductus arteriosus, typically seen in patients with Pulmonary atresia with intact septum (PA-IVS), Group 2: "intermediate" ductus arteriosus as seen in severe pulmonary stenosis (PS)-single ventricle, Group 3: "vertical" ductus arteriosus typically seen in patients with pulmonary atresia-ventricular septal defect, Group 4: ductus arteriosus arising from the aorta to a single lung, Group 5: ductus arteriosus arising from the innominate/subclavian artery to a single lung, Group 6: ductus arteriosus from innominate/subclavian artery to both lungs. RESULTS: Ductal stenting (DS) was attempted in 98 patients with 99 ducts. Successful stenting was possible in 83 patients. Success of DS was significantly different among the groups (p = .04, F = 5.41). Groups 1, 4, and 5 were "easy" with good success while Groups 2, 3, and 6 were complex and demanding. There were two deaths (after 5 and 7 days, respectively) that could be ascribed to DS. Elective re-interventions were performed in 34 ductuses (40%). Fifty three percent (n = 44/83) of successful ductus stents proceeded to further surgery and 20 ducts closed spontaneously in asymptomatic patients over time. CONCLUSIONS: Ductus arteriosus morphology influences technique and determines complexity, safety, and final outcome of ductus arteriosus stenting.

Percutaneous obliteration of the right ventricle to avoid coronary damage by sinusoids in patients with pulmonary atresia intact ventricular septum during staged single ventricle palliation.

BACKGROUND AND AIMS: Suprasystemic pressure waves can damage the coronary arteries resulting in myocardial ischemia and excess early mortality. We aimed to reduce the coronary pressure wave through the sinusoids by abolishing RV volume with percutaneous devices. METHODS AND RESULTS: Four patients with PA-IVS and coronary sinusoids from the hypertensive rudimentary RV were evaluated at a median age 26.6 months (range: 2.7-51.7). Right ventricle coronary dependent flow to the left ventricular myocardium was excluded. All four patients had dual perfusion with competitive flow from the RV through the sinusoids to the coronary arteries. Devices used were: Amplatzer vascular plug II of 10-16 mm; 27 coils (diameter 5-15 mm) in the oldest patient. Right ventricular angiography after cavity obliteration showed no more significant coronary perfusion through the sinusoids. There were no complications or deaths. Only minor and transient changes in the levels of troponin were observed. Coronary angiography at pre-Fontan evaluation showed no progress of coronary abnormalities in two patients. CONCLUSION: In selected patients with functionally single left ventricle, obliteration of the hypertensive RV cavity by percutaneous devices is safe and abolishes the systolic pressure wave in coronary sinusoids. When performed early, this may halt coronary damage and avoid excess mortality.

Percutaneous embolization of lymphatic fistulae as treatment for protein-losing enteropathy and plastic bronchitis in patients with failing Fontan circulation.

BACKGROUND: To determine the feasibility and clinical result of selective embolization of hepatoduodenal or paratracheal lymphatics in Fontan patients with protein-losing enteropathy (PLE) or plastic bronchitis (PB). METHODS: Dilated lymph vessels in periportal (PLE) or paratracheal (PB) position were percutaneously punctured with a 22G Chiba needle. Intralymphatic position was confirmed by water soluble contrast injection with drainage to hepatoduodenal or tracheal fistulae. After flushing with 10% glucose solution, occlusion of hepatoduodenal or paratreacheal lymphatics was effected by injection of 1-4 cc mixture 4/1 of Lipiodol/n-butyl cyanoacrylate (n-BCA; Histoacryl). RESULTS: Seven patients with proven PLE were treated with periportal lymphatic embolization 10.7 (range: 6.6-13.5) years after the Fontan operation. The Fontan operation was performed at a median age of 3.7 (range: 2.9-5.7) years and PLE started a median of 3.1 (range: 0.9-4.7) years later. Five patients required a second procedure 2-8 months later. Complications were limited (spillage of glue in portal branch, transient cholangitis, and caustic duodenal bleeding). Six of seven patients reported significant improvement in quality of life and normalization of albumin levels after limited follow-up (p < .01). One patient (Fontan at 2.9 years; age 16.4 years) had PB for 2 years. Selective transthoracic cone-beam-directed puncture of left and right paratracheal lymphatics with n-BCA embolization of distal lymphatic fistulae resulted in lasting absence of tracheal casts (11 months). CONCLUSIONS: Embolization of periportal/peritracheal lymphatics is a promising technique in Fontan patients with PLE/PB. Larger series are required to determine incidence and reasons of success/failure, with long-term results and effects on liver function.

Right ventricle outflow tract prestenting: In vitro testing of rigidity and corrosion properties.

BACKGROUND: The aim of this study was to assess the resistance to compression (stiffness) of frequently used stents for right ventricular outflow tract prestenting. In addition, to assess the corrosion potential when different types of stent alloys come into contact with each other. METHOD: Different stents were tested in vitro in various combinations at specialized metallurgic laboratories. A bench compression test was used to assess resistance to compression of singular and joined combinations of stents. Corrosion was evaluated by standardized electrochemical galvanic tests in physiological solutions at 37°C. Single stents and combinations of stents were evaluated over a period of 4-12 weeks. RESULTS: Relative stiffness of the stents Optimus/Andrastent XXL/Intrastent LD Max/8zig Cheatham-Platinum, expressed as load per length to deform the stent for 1 mm at 22 mm was 100/104/161/190. Adding additional stents to a single stent significantly strengthened the joined couples (P < 0.001). The lowest galvanic corrosion rates (about 0.000001 mm/year) were observed for the joined CP-Andrastent, Andra-Sapien, and Andra-SapienXT. The corrosion rate for coupled CP-Sapien and CP-SapienXT was somewhat higher (about 0.000003 mm/year). The materials with the highest corrosion rates resulted in material losses of, respectively, 17 and 24 µg/year, which is negligible over a lifetime. CONCLUSION: Adding stents to a single stent significantly increases stiffness which will reduce the risk of metal fatigue failure. Corrosion of individual stents or stent combinations occurs, but is negligible over a human lifetime with low risk of biological effects. No mechanical integrity problems are thus expected as there is only 0.3% of the initial diameter of the struts of a stent that will be lost as a consequence of corrosion after 100 years.

The effect of xenon-augmented sevoflurane anesthesia on intraoperative hemodynamics and early postoperative neurocognitive function in children undergoing cardiac catheterization: A randomized controlled pilot trial.

BACKGROUND: In adults, xenon has only minimal hemodynamic side effects when compared with other anesthetics. Moreover, in preclinical experiments, xenon has been demonstrated to possess cardio- and neuroprotective properties. Altogether, the favorable hemodynamic profile combined with its potential for organ-protection could render xenon an attractive option for anesthesia in children with cardiovascular compromise. AIMS: The aim of this study was to explore safety and feasibility of sevoflurane-augmented xenon anesthesia in school-aged children and to assess early postoperative neurocognitive effects of xenon-sevoflurane and sevoflurane anesthesia when compared to a control group that did not have anesthesia. METHODS: Forty children aged 4-12 years, suffering from congenital heart disease, undergoing diagnostic or interventional cardiac catheterization were randomized to either xenon-augmented sevoflurane anesthesia or sevoflurane alone. Safety was assessed by the incidence of intraprocedural hemodynamic instability and feasibility by anesthetic depth and respiratory profile. In addition, neurocognitive performance was assessed preoperatively, 2 hours after discharge from PACU and at 24 hours after anesthesia using the Amsterdam Neuropsychological Tasks system. A healthy control group of 22 age- and gender-matched children not exposed to anesthesia underwent an identical neurocognitive test battery, at comparable time intervals. RESULTS: Overall hemodynamics did not differ between groups. Xenon-sevoflurane anesthesia resulted in decreased intraoperative ephedrine requirements (median [IQR]) (0.00 mg/kg [0.00-0.00] vs 0.00 mg/kg [0.00-0.01], P = 0.047). Only neurocognitive tests in the domain of alertness were significantly impaired 2 hours postoperatively in both anesthesia groups in comparison with the control group (alertness variability: P = 0.02, odds ratio 5.8), but recovered at 24 hours. For working memory, inhibition, cognitive flexibility, and motor coordination tasks, no significant interaction effects of anesthesia were found in the early postoperative period. CONCLUSION: In this pilot trial, xenon-augmented sevoflurane anesthesia in school-aged children was feasible, and associated with decreased ephedrine requirements. All children exposed to anesthesia showed impaired neurocognitive performance in the immediate postoperative period when compared to control children; however, without significant differences between both treatment groups.

Right ventricular remodelling after transcatheter pulmonary valve implantation.

OBJECTIVES: To define the optimal timing for percutaneous pulmonary valve implantation (PPVI) in patients with severe pulmonary regurgitation (PR) after Fallot's Tetralogy (ToF) correction. BACKGROUND: PPVI among the aforementioned patients is mainly driven by symptoms or by severe right ventricular (RV) dilatation/dysfunction. The optimal timing for PPVI is still disputed. METHODS: Twenty patients [age 13.9 ± 9.2 years, (range 4.3-44.9), male 70%] with severe PR (≥3 grade) secondary to previous correction of ToF, underwent Melody valve (Medtronic, Minneapolis, MN) implantation, after a pre-stent placement. Full echocardiographic assessment (traditional and deformation analysis) and cardiovascular magnetic resonance evaluation were performed before and at 3 months after the intervention. 'Favorable remodelling' was considered the upper quartile of RV size decrease (>20% in 3 months). RESULTS: After PPVI, indexed RV effective stroke volume increased from 38.4 ± 9.5 to 51.4 ± 10.7 mL/m2 , (P = 0.005), while RV end-diastolic volume and strain indices decreased (123.1 ± 24.1-101.5 ± 18.3 mL/m2 , P = 0.005 and -23.5 ± 2.5 to -21 ± 2.5%, P = 0.002, respectively). After inserting pre-PPVI clinical, RV volumetric and deformation parameters in a multiple regression model, only time after last surgical correction causing PR remained as significant regressor of RV remodelling [R2 = 0.60, beta = 0.387, 95%CI(0.07-0.7), P = 0.019]. Volume reduction and functional improvement were more pronounced in patients treated with PPVI earlier than 7 years after last RV outflow tract (RVOT) correction, reaching close-to-normal values. CONCLUSIONS: Early PPVI (<7 years after last RVOT operation) is associated with a more favorable RV reverse remodelling toward normal range and should be considered, before symptoms or RV damage become apparent. © 2017 Wiley Periodicals, Inc.

Radiofrequency perforation of the pulmonary valve: an efficient low cost solution.

Objective The aim of the study was to assess the feasibility of using commonly available catheterization laboratory equipment for radiofrequency perforation of the pulmonary valve in patients with pulmonary atresia and intact ventricular septum. Methods The system (off-label use for all items) is made up of a co-axial telescopic arrangement consisting of a 0.014" PT 2 ™ coronary guidewire, for insulation inside a 2.7-F microcatheter which has an inner lumen of 0.021". The microcatheter was passed via a standard 4-F right coronary catheter to just below the atretic pulmonary valve. Radiofrequency (RF) energy was delivered using a standard electrosurgical system. In vitro testing had been performed and indicated that 5-10 W for 2-5 s would be sufficient for valve perforation. Results Radiofrequency perforation was successfully performed in all (n = 5, 100%) patients at a median age of 3 days (range: 1-36) and weight 2.7 kg (range 2.3-3.0). In one patient the pericardium was entered during the initial attempt; the generator was put on coagulation mode during retrieval of the guidewire and no haemopericardium occurred. The pulmonary valve was dilated in all; in three patients (n = 3) the ductus arteriosus was stented during the same session. Conclusion Results of the study show that it is feasible to perforate the pulmonary valve safely using this system. Availability, simplicity and cost are noteworthy benefits.

Percutaneous intervention for central shunts: new routes, new strategies.

Introduction In traditional locations, the standard Blalock-Taussig shunt presents numerous technical difficulties for percutaneous intervention. We changed our strategy to a central type shunt (Laks-type) with end-to-side pulmonary and side-to-side aortic anastomosis. The aim of this study was to determine whether this modified strategy would allow easier percutaneous manipulation in patients with small pulmonary arteries. Methods All children with a stretchable central vascular graft who required any form of percutaneous intervention were prospectively enrolled in the study. Results Eleven infants were evaluated a median time of 3 months (range 0.9-4.4) following initial shunt placement; the median weight at intervention was 5.7 kg (range: 4.0 - 10.0). All shunts (100%) were easily and swiftly entered without the need for special catheters or co-axial systems. In four patients other interventions in distal pulmonary arteries were first performed: cutting balloon treatment in three and balloon angioplasty of peripheral pulmonary artery stenosis in one. The shunts were then augmented with a stent with a diameter increasing from 3.5 ± 0.4 mm to 4.7 ± 0.8 mm and saturation increasing from 76% (range: 69-88) to 84% (range: 77-88) (P < 0.05). Several months later, two children required further interventions that could easily be performed via the stented shunts. No complications were observed. Conclusions The Laks-type shunt provides easy access for percutaneous procedures of the distal pulmonary arteries including cutting balloons; this shunt can predictably be expanded to augment pulmonary flow. This study highlights how co-operation between the interventionalist and the surgeon can improve strategies to manage these difficult patients.

Can a volume challenge pinpoint the limiting factor in a Fontan circulation?

OBJECTIVE: It is difficult to indicate whether the limitation in a failing Fontan circulation lies within the pulmonary vasculature or the heart. Such differentiation is crucial to direct adequate therapy. This study was set out to determine if a volume challenge could identify the limiting factor. METHODS AND STUDY POPULATION: Thirty-two catheterizations in 28 patients with a Fontan circulation were included. Pressures and oxygen saturations were measured before and after volume challenge (NaCl 0.9%; 15 cc/Kg). The changes in data were grouped based on the location of the major pressure increase. Ventricular function was measured in the resting state. RESULTS: The majority of the patients showed an increase in aortic oxygen saturation, mixed venous oxygen saturation, systolic, pulmonary and systemic venous pressures. The arterio-venous oxygen gradient decreased, suggesting an increase in cardiac output. Different patterns in pressure changes were observed. Most (n=17) showed a similar increase of ventricular end-diastolic pressure and mean venous pressure (MVP); some (n=7) showed a lower increase of MVP, suggesting pulmonary reserve and recruitment; others (n=8) showed a significant higher increase in MVP, suggesting increased pulmonary vascular resistance. All volume challenge was well tolerated. CONCLUSION: Most patients were preload-responsive. The pressure changes following volume load showed patterns with a potential of differentiating between patients with a major pulmonary or cardiac limiting factor.

Transventricular balloon dilation and stenting of the RVOT in small infants with tetralogy of fallot with pulmonary atresia.

INTRODUCTION: The management of small infants with tetralogy of Fallot (TOF) with pulmonary atresia (PA) and hypoplastic pulmonary arteries can be very challenging. METHODS: In three small infants (weight range 2,200-3,600 g, pulmonary trunk 2.0-3.2 mm), initial palliation consisted of sternotomy, transventricular puncture of the right ventricular outflow tract and atretic pulmonary valve, followed by balloon dilation (n = 1) or stent deployment (n = 2) from the right ventricle into the pulmonary trunk (stent diameter 5-6 mm, length 16 mm). RESULTS: The procedure resulted in adequate palliation with good anterograde flow to the pulmonary arteries and near normal saturations in all three patients (>92%); there was no associated morbidity. Additional transvenous stenting was required in all patients because of progressive muscular infundibular stenosis after a median of 3 months. Two patients evolved to full repair at the age of 5 months and one patient with multiple hilar stenoses requires additional percutaneous procedures through the stented RV outflow tract. CONCLUSION: Transventricular balloon dilation and stenting of the RVOT through medial sternotomy as initial palliation strategy appears a safe and well tolerated alternative treatment in small infants with TOF with PA and a hypoplastic pulmonary trunk.

Off-label use of percutaneous pulmonary valved stents in the right ventricular outflow tract: time to rewrite the label?

INTRODUCTION: Percutaneous pulmonary valve implantation is now considered feasible and safe. "Native" right ventricular outflow tract (RVOT), small diameter conduits (<16 mm) and relatively large RVOT with a dynamic outflow aneurysm are currently considered off-label uses. Extending indications creates concerns of safety, ethics, reimbursement, and liability. AIM OF STUDY: To report the safety and feasibility of off-label application of percutaneous pulmonary valve implantation. DESIGN: Retrospective analysis of prospectively collected data. PATIENTS AND METHODS: Off-label indications: conduit-free RVOT or patients with an existing but undersized conduit. RESULTS: Twenty-one Melody® valves and two Sapien® valves were successfully implanted in 23 patients (16.9 years; range 6.1-80.5 years). In 22 patients, prestenting was performed 4.8 months (range 0-69.2) before valve implantation (15 covered and 13 bare stents). Stent endothelial ingrowth was allowed for at least 2 months prior to implantation of the percutaneous valve if stent stability or sealing by the covering was presumed to be insufficient. Group 1 patients (n = 8) had a "conduit-free" RVOT after transannular/infundibular patch and after prestenting underwent percutaneous pulmonary valve implantation (PPVI), with a final RVOT diameter of 21.5 mm (range 16-26 mm). Group 2 patients consisted of two elderly patients with pulmonary valve stenosis and severe RVOT calcifications. Group 3 (n = 13) had an existing conduit (nominal 15.9 ± 3.2 mm; range 10-20 mm). The conduit was augmented from 14.7 ± 3.5 to 20 ± 1.6 mm with PPVI. The RVOT preparation and valve implantations were uneventful. CONCLUSIONS: PPVI is safe and feasible in selected patients with an off-label indication. Creating an adequate "landing zone" by prestenting makes the procedure safe and predictable. Updating the indications for PPVI should be considered.

Delivering stents in congenital heart disease using the double-wire technique: technical considerations.

OBJECTIVES: To evaluate the use of a double-wire technique to deliver stents. BACKGROUND: Placement of a stent in lesions close to bifurcations or without an anatomic obstruction can be problematic. PATIENTS AND METHODS: Stents were implanted in 12 patients between August 2010 and August 2012. Indications were complex anatomic obstruction in nine, external compression of pulmonary veins in two, and exclusion of an aortic aneurysm in one patient. RESULTS: Median age and body weight of the group were 11.6 years (range: 1.6-34.8) and 36 kg (range: 10-78), respectively. All stents were delivered safely and the patency of all side vessels was maintained; the distal end of the stent was flared to a median ratio of 1.4 (range: 1.2-1.8). The clinical objective was met in all patients: in lesions with stenosis, diameter increased from 5.9 mm (range: 1-13) to 9.9 mm (range: 8-17) [P < 0.01; 95% confidence interval (CI): 2.0-7.2]; oxygen saturations improved in the 2 patients after relief of the external pulmonary venous compression and in another an aortic aneurysm was excluded. One patient developed a hemothorax and one required blood transfusion for bleeding from the valve of the sheath. CONCLUSIONS: The double-wire stenting technique is effective to accurately deliver and anchor stents into lesions close to side branches and bifurcations. Side branch patency is maintained; the clinical objective (gradient relief, aneurysm exclusion, relief of external compression) can safely be reached. Technique and balloon selection should be based on the underlying anatomical substrate.

Percutaneous management of a Fontan fenestration: in search for the ideal restriction-occlusion device.

OBJECTIVE: Most devices devices available for percutaneous closure of Fontan fenestrations tend to be bulky. The aim of this study was to evaluate a low profile custom made device and assess its efficacy and safety. PATIENTS AND METHODS: A 15 mm PFO star was used as the basis. The following modifications were made: removal of the left disc to reduce thrombogenicity in the left atrium, increase the length of the LA legs from 2 by 15 mm to 3 by 20 mm to prevent dislodgement and later adding a pivot between the left and right umbrella. A partial occluder was made by removing two opposite quadrants from the proximal disk. RESULTS: Device deployment was possible in 93% (63 of 68) patients. In five patients, the device could not be deployed and an alternative device was used. In 45 patients complete closure of the fenestration was obtained and saturations increased from 84% +/- 4% to 95% +/- 2% (P < 001). In 18 high risk patients with suboptimal Fontan circulation, a modified device was used to effect partial occlusion: saturations increased from 79% +/- 7% to 90% +/- 4% (P < 0.001); a residual shunt persisted in most patients for several months. No thrombotic events were recorded during follow-up. CONCLUSIONS: The modified PFO star device can safely be deployed in Fontan patients to occlude or restrict flow through a fenestration. It has a low profile with minimal foreign material, is non-obstructive and minimally thrombogenic.

Bailout stenting for critical coarctation in premature/critical/complex/early recoarcted neonates.

BACKGROUND: Surgical repair of critical coarctation can be problematic in premature, critical, complex, or early postoperative neonates. OBJECTIVES: We aimed to review our experience with stent implantation to defer urgent surgery to an elective time. METHODS: Fifteen neonates with severe aortic coarctation: five premature-hypotrophic (1,400-2,000 g), six critical and complex cardiac malformation, four early (1 day [0-2 days]; median [range]) after surgical coarctectomy or complex arch reconstruction. Bare coronary stents (diameter 4.0 [3.5-5.0] mm; length 10 [8-16] mm) were used. Stents were removed surgically depending on clinical needs. RESULTS: Adequate aortic flow was obtained in 15 patients. The femoral artery was preserved in 13/15 patients. Two deaths occurred before stent removal and were nonprocedure related. In patients with simple stented coarctation, the stent was removed after 2.8 [0.2-5.0] months. In complex cardiac malformation, stents were finally removed 3.0 [0.2-78] months after implantation. SURGICAL TECHNIQUE: simple coarctectomy end-to-end in eight, extensive arch patch reconstruction in four. One patient is awaiting stent removal. The final maximum systolic velocity (cw-Doppler) across the aortic arch was 1.7 [1.2-2.5] m/sec. CONCLUSIONS: In premature/critical/complex neonates with severe coarctation, bailout stenting followed by early or late surgical coarctectomy appears a promising concept.

Stent expansion of stretch Gore-Tex grafts in children with congenital heart lesions.

OBJECTIVE: To evaluate the efficacy and safety of expanding vascular shunt grafts beyond original nominal diameter using stents. METHODS: Bench testing confirmed the expandability of 3.5 mm and 4.0 mm vascular Gore-Tex stretch grafts. A retrospective analysis included eleven systemic to pulmonary artery shunts with diminished flow which were stented with the aim of increasing the original nominal diameter of the shunts. RESULTS: During bench testing, the grafts could be expanded to 4.5 mm and 5.8 mm, respectively. Fourteen stents were implanted in 11 stretch grafts a median of 18.9 months (3.2; 21.6 months) after shunt surgery. There was a median increase in diameter of 1.4 mm (0.9; 1.7 mm) [P = 0.001, 95% CI: 0.47; 1.7) from original nominal to final stented diameter of the shunts with a median gain of 28%. A simultaneous improvement in saturations from a median of 73% (66; 77%) to 87% (84; 89%) [P = 0.015; 95% CI: 3; 22] was observed. No complications were experienced during the procedures. CONCLUSION: In our limited experience, stretch Gore-Tex vascular grafts can be safely expanded beyond nominal diameters using high pressure vascular stents. This leads to improvement in saturation and pulmonary blood flow. It allows the clinician to tailor pulmonary flow in relation to pulmonary artery size and growth, ensuring best possible timing for the next surgical procedure.

Use of a microcatheter in a telescopic system to reach difficult targets in complex congenital heart disease.

BACKGROUND: Some lesions can be very difficult to reach, especially if acute angles and/or multiple turns "protect" access. Once reached, the guiding system needs to give sufficient support for balloons or stents to be deployed. METHODS: A "telescopic" system was created consisting of: (1) a microcatheter with guidewire. This system fits into any catheter allowing a 0.035 inch wire. (2) a 4Fr "delivery" catheter. (3) If sharp angles were encountered, the 4Fr catheter was deployed through a 6Fr or larger angulated guiding sheath. This was cut-off 15 cm out of the groin and re-valvulated with a standard short introducer sheath. PATIENTS AND RESULTS: Since 2004, 89 microcatheter telescopic systems were used during a 4-year period in 1,225 procedures (7.3%). The technique allowed probing with a floppy steerable and exchangeable guidewire, securing any gained position as well as exchanges with a stiffer guide wire if required. Procedures where the telescopic system was effective included: complex stenoses e.g. aortopulmonary collaterals (n = 21), tortuous ducts (n = 9), anterograde balloon dilation of critical aortic stenosis (n = 8) and crossing Blalock Taussig shunts (n = 3). Once in place, the telescopic system allowed delivery of embolic material (n = 38), balloon angioplasty (n = 21), stent deployment (n = 23), fulguration of pulmonary valve (n = 1) or introduction of medication (n = 1). The interventionalists felt that using the telescopic system had reduced fluoroscopy and procedure time. CONCLUSIONS: The microcatheter-telescopic system is an invaluable tool to reach difficult targets and allows exchange for suitable guidewires permitting balloons, stents, embolisation material or radiofrequency energy to be deployed in such targets. This approach has become our standard when dealing with difficult targets protected by a tortuous route.

Clinical Characteristics of Infective Endocarditis in Children.

BACKGROUND: Infective endocarditis (IE) remains a diagnostic and therapeutic challenge associated with high morbidity and mortality. We evaluated the microbial profile and clinical manifestation of IE in children. METHODS: A retrospective study examining pediatric IE cases treated between 2000 and 2017 at the Department of Pediatric Cardiology, KU Leuven, was conducted. Clinical presentation, treatment, complications, outcome of IE, underlying microorganisms and congenital heart defects were reviewed. RESULTS: Fifty-three patients were diagnosed with IE. Overall, 19 patients (36%) required cardiac surgery. Seven patients (13%) died. Eighty-seven percent of patients had an underlying congenital cardiac defect. Eighteen (34%) children presented with prosthetic graft IE. A causative organism was found in 49 (92%) cases: viridans group streptococci were identified in 17 (32%), Staphylococcus aureus in 13 (25%) and coagulase-negative staphylococci in 11 (20%) children. Community-acquired (CA) IE increased significantly from 8 (33%) cases in 2000-2007 to 20 (74%) cases in 2008-2017 (P < 0.01). Even with viridans streptococci being significantly more prevalent in the CA group (P < 0.01), we did not observe an increase of streptococcal IE from 2008 to 2017. Seventeen (32%) patients presented with hospital-acquired IE during the first year of life with 14 (82%) children after surgery and a prevalence of coagulase-negative staphylococci (53%). CONCLUSIONS: The incidence of pediatric IE was similar over the investigated time period with a shift toward CA IE. Streptococci and staphylococci accounted for the majority of cases in both periods. Awareness of IE and its prevention is crucial in patients after implantation of prosthetic grafts.

Safety and efficacy of clopidogrel in children with heart disease.

OBJECTIVE: To evaluate the efficiency and safety of clopidogrel treatment in children with heart disease. STUDY DESIGN: We conducted single center retrospective chart review of children with heart disease at the University Hospital, Leuven, Belgium, in whom clopidogrel was used. The indication, dosage, duration of therapy, and adverse events were examined. Clinical efficacy was defined by an absence of thrombotic events. RESULTS: 46 children were identified. The mean age of first clopidogrel dose was 4.9 +/- 4.1 years. The study dosage ranged from 0.1 to 0.7 mg/kg/day clopidogrel. Almost all patients received concomitant aspirin therapy. No thrombotic events developed. Skin bruising developed in almost every patient, suggesting that clopidogrel has an anti-platelet effect. 2 patients who were treated with concomitant warfarin had bleeding complications (severe epistaxis and gastrointestinal bleeding). Hematological abnormalities were documented in 1 patient who received clopidogrel for 1 year; they reversed with medication cessation. CONCLUSION: Clopidogrel therapy in a pediatric population appears to be relatively safe and effective; however, randomized, controlled prospective studies are needed to determine the true efficacy and safety of clopidogrel in children.

Up to 11 years of experience with the Melody valved stent in the right ventricular outflow tract.

AIMS: The aim of the study was to report up to 11 years of follow-up after Melody valve implantation in the pulmonary position. METHODS AND RESULTS: This was a single-institution non-randomised prospective observational study of all Melody valves in the pulmonary position after discharge between 2006 and 2017 (n=188). Mean age was 19.4 years (SD 13.2). The indication was stenosis (45%), regurgitation (33%) and mixed (22%). Pre-stenting was performed in all except the initial four patients. In stenotic lesions the peak gradient was 36 mmHg PIG (SD 12.0) after 11 years and in regurgitant lesions the maximal regurgitation was 2/4. Stent fractures were observed in 8.6%; only one grade III fracture required redo PPVI. Surgical removal was carried out in seven (3.7%), redo PPVI in five (2.7%). Endocarditis was diagnosed in 19 (10.2%) patients at a median of 2.3 years (0.7-8.8) after Melody implantation. Three were surgically removed early because of persistent infection, 16 were sterilised; six required replacement (three surgical, three redo PPVI). There were no valve- or procedure-related deaths. CONCLUSIONS: The Melody valve shows a good preserved leaflet function up to 11 years after implantation. The main reason for graft failure was endocarditis, although in half of those patients no reintervention was needed. After pre-stenting, stent fractures led very exceptionally to reintervention.