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Lee N Benson

Publications and source records attributed to Lee N Benson.

At least 37 records · Page 2Linked to original sources
PubMed2004

Outcomes and alternative techniques for device closure of the large secundum atrial septal defect.

Outcomes of device closure of large and small secundum atrial septal defects (ASDs) as related to rim anatomy with the Amplatzer atrial septal occluder were compared. Rim adequacy (> or = 5mm) of the anterior, inferior, posterior, and superior rims was determined using transesophageal echocardiography. Balloon-stretched defect size defined patients into two groups: group 1, < or = 25 mm (n = 138); group 2, > 25 mm (n = 34). Rim deficiency (n = 62) was more frequent in group 2 compared to group 1 (50% vs. 33%; P = 0.07), especially inferior rim deficiency (35% vs. 2%; P = 0.005). Device deployment was successful in group 1 and group 2 (100% vs. 91%; P = 0.007). Unsuccessful deployment was associated with an ASD of > 25 mm (P = 0.007) and inferior rim deficiency (P = 0.001). At first follow-up (54 +/- 16 days), right ventricular systolic pressure had improved in both groups (P < 0.001). Closure of a large ASD associated with a lack of support in the inferior rim may warrant alternative strategies to position the device successfully.

Adult↗
PubMed2004

Bladed balloon angioplasty for peripheral pulmonary artery stenosis.

Treatment for peripheral pulmonary artery stenosis is challenging, and conventional balloon angioplasty has not proved to be universally effective. Evaluated was the efficacy of bladed balloon (BB) dilation to address vessels resistant to conventional high-pressure (10-15 atm) balloon angioplasty (BA). Thirty-one procedures were performed on 14 children with age range 1 month to 15 years. The diameter of the BB ranged from 3 to 8 mm. After BB dilation, all children had subsequent conventional BA (balloon size range, 3-10 mm). The minimal lumen diameter (MLD) before and after the procedure, whether there was a waist at initial BA, and BB diameter-to-MLD ratio before the procedure were measured. A > 50% increase in MLD was considered successful. Four children had Williams syndrome, two children Alagille syndrome, five children Fallot's tetralogy, and three miscellaneous lesions. The resistant stenosis was located in the right central pulmonary artery in 6, right branch pulmonary artery in 7, left central pulmonary artery in 6, and left branch pulmonary artery in 12 lesions. Median BB diameter was 253% (117-440%) of the MLD and increased from 2.0 +/- 0.7 to 3.2 +/- 0.8 mm (P < 0.0001), with a mean increase of 73% +/- 62%. There was an inverse relationship between the MLD before and increase after the procedure (r = 0.75; P < 0.001). The BB diameter-to-MLD ratio before procedure was significantly associated with the increase in MLD (r = 0.70; P < 0.001). After the procedure, 18 of the 31 procedures were considered successful. In all successful procedures, the BB diameter was greater than twice the MLD before the procedure. Comparing children with Williams and Alagille syndrome with the remaining eight children, there were no significant differences in the increase in MLD. A small aneurysm and thrombus were noticed in two and three children, respectively, but no fatal complications were reported. BB angioplasty is effective for resistant peripheral pulmonary artery stenosis when conventional BA fails. The diameter of the BB should be larger than twice the minimal luminal diameter of the stenotic lesion.

Adolescent↗
PubMed2004

Clinical outcomes of patent foramen ovale closure for paradoxical emboli without echocardiographic guidance.

The objective of this study was to determine the feasibility of device closure of patent foramen ovale (PFO) for presumed paradoxical emboli without echocardiographic guidance or balloon sizing and the clinical outcome after device closure. Closure of the PFO has been proposed as an alternative to anticoagulation in patients with presumed paradoxical emboli. At present, most centers perform device closure with transesophageal echocardiographic guidance and balloon sizing of the defect. Between May 1998 and April 2002, 92 consecutive patients underwent device closure for a PFO using fluoroscopic monitoring only. Procedural success and major complications were recorded. Follow-up outcomes were recurrence rate and residual atrial shunting on transthoracic echocardiography. All patients (mean age, 45 +/- 13 years; 52% male) had successful device deployment using either the CardioSeal (n = 78) and Amplatzer (n = 14) PFO occluders with no major complications. Mean procedure time and fluoroscopy time was 27 +/- 13 and 6 +/- 4 min, respectively. One patient had a residual shunt on echocardiography at 1 year. Cumulative event-free survival for recurrence of paradoxical embolus at 1 year was 97.3% +/- 1.8%. This study provides a basis for device closure of PFO becoming a safe, day-case procedure, resulting in a low rate of residual shunting and recurrent thromboembolic events.

Adult↗
PubMed2004

Pulmonary atresia with intact ventricular septum: management of, and outcomes for, a cohort of 210 consecutive patients.

OBJECTIVES: We sought to determine trends, and outcomes, for a cohort of patients with pulmonary atresia with intact ventricular septum born between 1965 and 1998. BACKGROUND: Pulmonary atresia with intact ventricular septum is a complex lesion that remains a therapeutic challenge, particularly regarding the suitability for biventricular repair. METHODS: We identified 210 consecutive patients, and reviewed their medical records, initial angiograms, and echocardiograms, along with the relevant surgical and pathology reports. RESULTS: The mean initial Z-score for the diameter of the tricuspid valve was -0.99 +/- 1.95, with Ebstein's malformation in 8%. A right ventricular dependent coronary arterial circulation was found in 23%. The proportion of patients who received treatment increased over time, although placement of an arterial shunt was the predominant initial procedure throughout the experience. At the last follow-up, 107 patients had not reached the planned final stage of their repair, and 79% of these had died. Of the 103 reaching the final stage of planned repair, 58 had undergone attempted biventricular repair, with 34% dying; 14 had undergone attempted one and a half ventricular repair, with 7% dying, and 31 had undergone attempted functionally univentricular repair, with 10% dying. Overall, survival was 57% at the age of 1 year, 48% at 5 years, and 43% at 10 years. Survival improved over time, with survival of 75% at 1 year, and 67% at 5 years, for patients born between 1992 and 1998. An earlier date of birth, the presence of Ebstein's malformation, and prematurity were all significant independent factors associated with decreased survival. A greater severity of coronary arterial abnormalities was significantly associated with a greater likelihood of left ventricular dysfunction during follow-up. CONCLUSIONS: The outcomes for patients born with pulmonary atresia with intact ventricular septum have improved over time, albeit that careful initial management, and better selection, is still indicated for those planned to undergo biventricular repair.

Cardiac Surgical Procedures↗
PubMed2004

Outcomes after balloon dilation of congenital aortic stenosis in children and adolescents.

OBJECTIVES: To determine the long-term outcomes and risk factors for, reintervention after balloon dilation of congenital aortic stenosis in children aged 6 months or older. BACKGROUND: Although balloon dilation of congenital aortic stenosis has become a primary therapeutic strategy, few data are available regarding long-term outcomes. METHODS: We carried out a retrospective review of 87 children who had undergone balloon dilation of the aortic valve at median age of 6.9 years. RESULTS: The procedure was completed in 98% of the children, with an average reduction in the gradient across the valve of 64 +/- 28%, and without mortality. Of the children, 76 had been followed for a mean of 6.3 +/- 4.2 years. Reintervention on the aortic valve was required in 32 children, with 12 undergoing reintervention within 6 months, with 1 death. Another patient had died over the period of follow-up due to a non-cardiac event. Estimated freedom from reintervention was 86% at 1 year, 67% at 5 years, and 46% at 12 years. Parametric modeling of the hazard function showed a brief early phase of increased risk, superimposed on an ongoing constant risk. The only incremental risk factor for the early phase was a residual gradient immediately subsequent to the procedure greater than 30 mmHg. Incremental risk factors for the constant phase included the presence of symmetric valvar opening, and greater than moderate regurgitation immediately after dilation. CONCLUSION: Long-term survival was excellent, albeit that the need for further reintervention was high due to the palliative nature of the procedure.

Adolescent↗
PubMed2004

Radiofrequency applications in congenital heart disease.

The relatively recent application of radiofrequency technologies in the treatment of congenital heart defects has provided a safe and effective alternative to conventional therapies in establishing endovascular patency for a variety of lesions. Radiofrequency, with typically used frequencies of approximately 500 kHz, does not cause pain and is unlikely to induce atrial or ventricular fibrillation. It can be used either to ablate (higher power (35-50 W); longer duration of application (90-120 sec); lower voltage (30-50 V)) or to perforate (lower power (5-10 W) shorter duration of application (1-5 sec), higher voltage (150-280 V)). In the past, perforating radiofrequency has been applied to establish right ventricular outflow tract patency in pulmonary atresia with intact septum and with ventricular septal defect. More recently radiofrequency has been shown to be effective at recanalizing central and peripheral vasculature and has also been applied in establishing percutaneous left heart access. A new radiofrequency catheter, dedicated to transseptal left atrial cannulation, has been demonstrated to be safe and effective in an animal model and is now ready for clinical trials.

Adolescent↗
PubMed2003

Percutaneous balloon valvotomy in pulmonary atresia with intact ventricular septum: impact on patient care.

BACKGROUND: Pulmonary atresia with intact ventricular septum (PA-IVS) is a rare congenital lesion with high mortality. Therapy was exclusively surgical until recently, when the use of radiofrequency-assisted perforation of the atretic valve was introduced as a treatment option. This study analyzes the outcomes and morphological changes to right heart structures after percutaneous perforation and balloon dilation of the atretic valve. METHODS AND RESULTS: Between April 1992 and August 2000, 30 patients with PA-IVS underwent attempted percutaneous valve perforation and balloon dilation of the pulmonary valve. Longitudinal echocardiographic measurements of the tricuspid valve diameter, right ventricular length and area were recorded. Z scores were calculated according to published formulas. Perforation was achieved in 27 patients. In 14 patients a modified Blalock-Taussig shunt was performed between 2 and 24 days after valve dilation. There were 3 early and 2 late deaths. Among the survivors (follow-up time of 1 to 87 months), 16 patients had a biventricular circulation, 3 a 1(1/2)-ventricle circulation, and 1 a Fontan operation. Four patients are awaiting further palliation. There was no significant change of the tricuspid valve Z score or right ventricular length Z score with time. CONCLUSIONS: Percutaneous balloon valvotomy is an effective treatment strategy for patients with PA-IVS provided that there is a patent infundibulum and a lack of a right ventricle-dependent coronary circulation. Despite the observation that right heart growth does not increase with body growth in early follow-up, it appears adequate to maintain a biventricular circulation in many patients.

Angiography↗
PubMed2003

Intracardiac echocardiography guided device closure of atrial septal defects.

OBJECTIVES: This study was designed to determine the feasibility and accuracy of intracardiac echocardiography (ICE) in guiding percutaneous closure of atrial septal defects (ASD). BACKGROUND: Intracardiac echocardiography is a novel imaging technique that might be used to guide interventional procedures. The sensitivity and specificity of ICE, compared to standard imaging techniques, in detecting potentially adverse procedural events and guiding remedial action will be an important consideration in its use. METHODS: In a prospective study, 24 patients underwent device closure of ASD using ICE as the primary echocardiographic imaging modality. Feasibility was expressed as proportion of cases in which complete diagnostic ICE imaging was achieved. Accuracy was expressed as the percent agreement between ICE and simultaneously performed transesophageal echocardiography (TEE). RESULTS: High-quality ICE images were acquired in all patients, though images were limited in two patients with aneurysmal septa. Intracardiac echocardiography successfully guided closure of 24 out of 25 ASDs (96%) in 23 patients. There was close agreement between ICE and TEE in their assessment of device position and the adequacy of septal capture before device release (98%) and in identifying the presence of significant residual shunts. Intracardiac echocardiography detected all potentially adverse events, including four malpositions, and guided appropriate remedial action. CONCLUSIONS: Intracardiac echocardiography guided device closure of secundum ASDs is feasible in the majority of patients and provides diagnostic data comparable to TEE. These data indicate that ICE may be used to guide routine closure of ASDs in adults without the need for TEE and general anesthesia.

Adolescent↗
PubMed2003

The Genesis stent: A new low-profile stent for use in infants, children, and adults with congenital heart disease.

Placement of intravascular stents that can reach adult size in infants and smaller children has been limited by the large profile and poor flexibility of currently available stents. In vitro and in vivo testing of the Genesis stent was performed to evaluate crimpability, predeployment flexibility, and radial strength. Comparisons were made to the Palmaz iliac and IntraStent (IS) LD stents. Nine physicians placed 30 Genesis stents in swine pulmonary and systemic arteries to evaluate stent deliverability/crimpability. Two swine were recovered and underwent a second catheterization 8 weeks later, where the stents (n = 8) were reexpanded to maximal size. Angiographic and intravascular ultrasound (IVUS) assessments were performed. In vitro testing revealed the Genesis stent to have superior crimpability, flexibility, and comparable radial strength to the Palmaz iliac stent, and superior crimpability and radial strength and comparable flexibility to the IS LD series. During in vivo testing, the physicians graded the Genesis stent superior to the Palmaz stent regarding crimpability and deliverability, and superior to the IS LD stent in regard to crimpability, and comparable to or superior in deliverability. In the chronic animals, the Genesis stent was expanded up to maximal diameter 8 weeks following implantation. Angiographic and IVUS revealed no fractures no in-stent restenosis. The Genesis stent can be easily delivered through smaller sheaths, which will facilitate their use in infants and smaller children with vascular stenosis.

Adult↗
PubMed2003

Outcomes of uncomplicated aortic valve stenosis presenting in infants.

BACKGROUND: The management of uncomplicated aortic valve stenosis presenting with critical obstruction in infants continues to be associated with significant morbidity and mortality. However, not all infants have critical obstruction, and outcomes spanning the broader spectrum of disease severity are less well defined. METHODS: In a 12-year period, 55 infants (<3 months of age) were seen with aortic valve stenosis and with anatomy suitable for biventricular repair. Clinical, echocardiographic, angiographic, management, and outcome data were reviewed. RESULTS: Status at presentation (median age 6 days) included signs of congestive heart failure in 20 patients, cardiovascular collapse in 5 patients, and an asymptomatic heart murmur in 30 patients. The initial echocardiogram showed reduced left ventricular function in 26% of patients, with a mean peak instantaneous gradient of 69 +/- 30 mm Hg in patients with normal function. There were 5 deaths (9%), all in patients with poor ventricular function. The initial intervention was balloon valvotomy in 24 patients and surgical valvotomy in 20 patients, with 11 patients having no intervention to date. The freedom-from-intervention rate was 69% at age 1 week, 58% at 1 month, 36% at 3 months, and 28% at 1 year. Patients without cardiovascular collapse, normal left ventricular function, and gradients <60 mm Hg at presentation (n =1 9) had better survival and longer freedom from intervention than patients with poor ventricular function or gradients >or=60 mm Hg (n = 36, P =.0001). CONCLUSION: Most infants with aortic valve stenosis receive intervention, although this may be safely delayed in selected patients with lower initial gradients and good left ventricular function.

Aortic Valve↗
PubMed2003

Anatomic repair of anomalous left coronary artery from the pulmonary artery by aortic reimplantation: early survival, patterns of ventricular recovery and late outcome.

BACKGROUND: To determine the early and late outcomes of patients presenting with anomalous left coronary artery from the pulmonary artery who had repair by aortic reimplantation. METHODS: From January 1952 to July 2000, 67 patients presented with anomalous coronary artery from the pulmonary artery. Forty-seven patients who had repairs performed by aortic reimplantation are the subject of this study. The median age at repair was 7.7 months. Before repair, 10 infants (21%) presented in extremis requiring ventilatory and inotropic support, and 38 infants (80%) presented in heart failure. Autologous pericardial hood coronary arterioplasty was used in 4 patients, and concomitant mitral valve repair was used in 1 patient. RESULTS: Hospital survival was 92%. Five children required postoperative extracorporeal membrane oxygenation for a median of 4 days (range, 2 to 8 days). Patients who had extracorporeal membrane oxygenation were significantly more likely to have presented in critical condition (40% vs 3% if no extracorporeal membrane oxygenation; p = 0.006) or with ventricular arrhythmias (67% vs 7%; p = 0.027), to have presented with significantly lower preoperative repair median ejection fraction (10%, n = 5 vs 40%, n = 38; p = 0.01) or to have presented with more severe left ventricular dilatation (p = 0.03). Within a 15-year or less follow-up (mean, 4.7 years) there were no late deaths. Kaplan-Meier survival was 91% at 5 years, and freedom from reoperation was 93% at 10 years. At late follow-up, echocardiography demonstrated significant improvements in mean ejection fraction (64% +/- 9% vs 33% +/- 21% preoperatively, p < 0.0001); moderate mitral regurgitation (9% vs 38% preoperatively, p < 0.02); and wall motion abnormalities (15% vs 81% preoperatively, p < 0.002). The ratio of measured left ventricular end-diastolic dimension to the 95th percentile of normal declined from 1.4 +/- 0.3 to 1.0 +/- 0.1 (p < 0.0006). Children who had extracorporeal membrane oxygenation had normal ejection fractions and ventricular dimensions at follow-up (n = 3). Repeated measures of mixed linear regression analysis demonstrated that normalization of ejection fraction and left ventricular function occurred within 1 year of repair. Improvements in mitral regurgitation lagged behind normalization of ejection fraction and left ventricular dilatation. CONCLUSIONS: Anatomic repair of anomalous left coronary artery from the pulmonary artery by aortic reimplantation yields excellent early survival and late functional outcomes even in critically ill infants.

Adolescent↗
PubMed2003

Interventional strategies in the management of peripheral pulmonary artery stenosis.

Peripheral pulmonary artery stenosis challenges therapeutic algorithms for the management of congenital heart malformations. Surgical repair of the proximal pulmonary artery lesion remains with a high recurrence rate while the distal lesions are difficult to access. With the development of transcatheter interventional strategies in the early 1980s, a number of transcatheter treatment options became available. In this review, we summarize the current state of the art for interventional strategies in the management of peripheral pulmonary artery stenosis.

Alagille Syndrome↗
PubMed2003

Characterization and treatment of systemic venous to pulmonary venous collaterals seen after the Fontan operation.

OBJECTIVES: To determine the anatomical characteristics of systemic venous collaterals formed after the Fontan operation, and the efficacy of a transcatheter strategy for management. METHODS: We reviewed retrospectively the data from cardiac catherization of 50 persistently cyanotic patients after the Fontan operation. RESULTS: A total of 54 transcatheter interventions were performed, at a mean age of 6.3 +/- 3.5 years, a mean interval of 2.7 +/- 2.9 years from completion of the Fontan circulation. Of 38 patients who had fenestration of the baffle at the time of surgery, 25 had patency of the fenestration, and 24 had the fenestration occluded with a device at the time of interventional treatment for associated venous collaterals. We identified a total of 68 systemic venous collateral channels, of which 36 (53%) were supracardiac, 12 (18%) cardiac, and 20 (29%) infracardiac in origin. The most common site of origin was the brachiocephalic vein (44%), followed by the left phrenic vein (25%). A longer time from surgery, at 3.3 +/- 3.4 years, was associated with the identification of collaterals having a diameter larger than 4 mm (p < 0.01). The mean pulmonary arterial pressure was higher in those with larger compared to those with smaller collaterals (13.3 +/- 2.8 versus 11.1 +/- 2.0 mmHg, p < 0.01). Coils were used for occlusion of 61 vessels, and a Rashkind occluder for the remaining 7. After exclusion of the patients undergoing simultaneous closure of their fenestration, systemic saturation of oxygen increased from 89 +/- 6% to 95 +/- 3% (p < 0.01). CONCLUSION: Venous collateral channels are common in patients suffering progressive cyanosis in the setting of the Fontan circulation. The collaterals increase in size with time, and are associated with higher pulmonary arterial pressures. Transcatheter treatment is feasible, and results in resolution of cyanosis. Only continuing follow-up will show whether further collateralization occurs in time.

Canada↗
PubMed2002

Radiofrequency perforation in the treatment of congenital heart disease.

Catheter-directed perforation of cardiac tissue with radiofrequency (RF) energy has expanded the horizon of the interventional cardiologist dealing with congenital heart disorders. The focus of the following discussion will be to detail the biophysical basis behind RF perforation and review its application in the management of congenital heart lesions.

Animals↗
PubMed2002

Catheter interventions in adult patients with congenital heart disease.

Adult patients with congenital heart disease provide a wide variety of challenges for the interventional cardiologist. Procedures can broadly be divided into dilatation or closure. The most common interventions in our own practice are closure of atrial septal defects and patent foramen ovale, although closure of postoperative interatrial communications in Mustard, Senning, or Fontan patients is also possible. Transcatheter patent ductus arteriosus closure is also now routine, and occlusion of coronary artery fistulae can be safely attempted using coil embolisation. Balloon dilatation of pulmonary valve stenosis has excellent success rates, and dilatation or stenting of pulmonary artery stenoses is also beneficial in selected cases. Although aortic valve dilatation in adults has mixed results, dilatation or stenting of aortic coarctation is now becoming more widespread, and has promising results. Dilatation procedures may also be applicable to the postoperative patient with conduit or baffle stenosis.

Adult↗
PubMed2002

Cineangiographic aortic dimensions in normal children.

Knowledge of normal aortic dimensions is important in the management of children with aortic disease. So as to define such dimensions, we undertook a retrospective review of clinical data and aortic cineangiograms from 167 subjects without aortic disease having a mean age of 3.67 years, with a range from 0.01 to 14.95 years. Amongst the patients, 56 were without detectable cardiac lesions, 66 patients had mild pulmonary stenosis, 30 were seen with Kawasaki disease, and 15 with small interatrial defects within the oval fossa. Aortograms were available in all. No patient had any hemodynamic derangement that would have affected the aorta during intrauterine life or childhood. Systolic dimensions were measured in the ascending and descending aorta at the level of the carina, at the transverse aortic arch distal to the brachiocephalic, of the left common carotid artery at its origin, at the transverse aortic arch distal to the left common carotid artery, at the aortic isthmus, and of the aorta at the level of the diaphragm. A regression analysis model was used to establish the range of predicted normal values, with their confidence limits, standardizing the values to height as the biophysical parameter having the highest correlation to aortic dimensions. Normal ranges were established for all the levels of measurement. The data should prove useful in identifying abnormalities of the thoracic aorta during childhood, and when assessing the outcomes of interventions.

Adolescent↗