Successful Device Implantation Research Articles

Percutaneous Aortic Valve Replacement for Severe Aortic Stenosis in High-Risk Patients Using the Second- and Current Third-Generation Self-Expanding CoreValve Prosthesis: Device Success and 30-Day Clinical Outcome

We sought to determine both the procedural performance and safety of percutaneous implantation of the second (21-French [F])- and third (18-F)-generation CoreValve aortic valve prosthesis (CoreValve Inc., Irvine, California). Percutaneous aortic valve replacement represents an emerging alternative therapy for high-risk and inoperable patients with severe symptomatic aortic valve stenosis. Patients with: 1) symptomatic, severe aortic valve stenosis (area <1 cm2); 2) age > or =80 years with a logistic EuroSCORE > or =20% (21-F group) or age > or =75 years with a logistic EuroSCORE > or =15% (18-F group); or 3) age > or =65 years plus additional prespecified risk factors were included. Introduction of the 18-F device enabled the transition from a multidisciplinary approach involving general anesthesia, surgical cut-down, and cardiopulmonary bypass to a truly percutaneous approach under local anesthesia without hemodynamic support. A total of 86 patients (21-F, n = 50; 18-F, n = 36) with a mean valve area of 0.66 +/- 0.19 cm2 (21-F) and 0.54 +/- 0.15 cm2 (18-F), a mean age of 81.3 +/- 5.2 years (21-F) and 83.4 +/- 6.7 years (18-F), and a mean logistic EuroSCORE of 23.4 +/- 13.5% (21-F) and 19.1 +/- 11.1% (18-F) were recruited. Acute device success was 88%. Successful device implantation resulted in a marked reduction of aortic transvalvular gradients (mean pre 43.7 mm Hg vs. post 9.0 mm Hg, p < 0.001) with aortic regurgitation grade remaining unchanged. Acute procedural success rate was 74% (21-F: 78%; 18-F: 69%). Procedural mortality was 6%. Overall 30-day mortality rate was 12%; the combined rate of death, stroke, and myocardial infarction was 22%. Treatment of severe aortic valve stenosis in high-risk patients with percutaneous implantation of the CoreValve prosthesis is feasible and associated with a lower mortality rate than predicted by risk algorithms.

Transcatheter embolisation of patent ductus arteriosus using an Amplatzer vascular plug in six dogs

The objective of this study was to assess the feasibility of transcatheter embolisation of a patent ductus arteriosus using an Amplatzer vascular plug (Amplatzer Medical UK) in six dogs. The Amplatzer vascular plug is a self-expandable, cylindrical device attached to a delivery cable. In all the dogs, the device was delivered transvenously. Successful device implantation was defined as firm anchorage of the device squarely within the distal part of the ductus arteriosus with no intra- or postoperative dislodgement. Successful occlusion of the ductus arteriosus occurred if a disappearance of the continuous murmur was achieved 24 hours after placement of the Amplatzer vascular plug. The age of the dogs ranged from 16 weeks to 7.5 years. Their weights ranged from 2.9 to 27.6 kg (median 6 kg). Two dogs had congestive heart failure before embolisation. Successful device implantation was achieved in all dogs. Successful occlusion of the ductus arteriosus was achieved in four of the six dogs. Complications included mild lameness, residual shunting, and bruising and pruritus around the surgical wound site. At follow-up, two dogs had a continuous murmur and one required treatment for congestive heart failure. This technique may represent a clinically effective and less expensive alternative to the use of an Amplatzer duct occluder (Amplatzer Medical UK) in dogs with medium-sized patent ductus arteriosus. Further investigations are required to fully evaluate its efficacy and safety in various sizes and types of patent ductus arteriosus, and to determine the optimal device size in relation to the size of the ductus.

BioSTAR Evaluation STudy (BEST)

The use of permanent synthetic implants to close atrial septal defects (ASD) and patent foramen ovale (PFO) has a number of limitations, including late complications and the limiting of transeptal access to the left heart should it be required for the later treatment of acquired heart disease. BioSTAR is a novel, bioabsorbable, atrial septal repair implant. This phase I pilot study evaluates the feasibility, safety, and effectiveness of BioSTAR for the first time in humans. We conducted a prospective, open-label, multicenter clinical study in 58 patients aged 28 to 68 years who had a clinically significant ASD or PFO. Percutaneous shunt closure was undertaken with the BioSTAR septal repair implant. Successful device implantation was achieved in 57 (98%) of 58 patients. Closure at 30 days and 6 months, assessed by contrast transthoracic echocardiography, was 48 (92%) of 52 and 54 (96%) of 56, respectively. There was no evidence of a clinically significant response to the device. Transient atrial arrhythmia occurred in 5 patients after implantation. No major safety issues were observed. This study demonstrates the feasibility, safety, and effectiveness of BioSTAR for the closure of ASD and PFO in humans with a high rate of early and complete shunt closure. BioSTAR is a novel septal repair implant designed to provide biological closure of atrial-level defects using the patient's natural healing response. Because 90% to 95% of the implant is absorbed and replaced with healthy native tissue, future access to the left atrium may be achieved.

Percutaneous Implantation of the CoreValve Self-Expanding Valve Prosthesis in High-Risk Patients With Aortic Valve Disease

The morbidity and mortality of surgical aortic valve replacement are increased in elderly patients with multiple high-risk comorbid conditions. Therefore, a prospective, single-center, nonrandomized study was performed in high-risk patients with aortic valve disease to evaluate the feasibility and safety of percutaneous implantation of a novel self-expanding aortic valve bioprosthesis (CoreValve). Symptomatic high-risk patients with an aortic valve area <1 cm2 were considered for enrollment. CoreValve implantation was performed under general anesthesia with extracorporeal support using the retrograde approach. Clinical follow-up and transthoracic echocardiography were performed after the procedure and at days 15 and 30 after device implantation to evaluate short-term patient and device outcomes. A total of 25 patients with symptomatic aortic valve stenosis (mean gradient before implantation, 44.2+/-10.8 mm Hg) and multiple comorbidities (median logistic EuroScore, 11.0%) were enrolled. Device success and procedural success were achieved in 22 (88%) and 21 (84%) patients, respectively. Successful device implantation resulted in a marked reduction in the aortic valve gradients (mean gradient after implantation, 12.4+/-3.0 mm Hg; P<0.0001). The mean aortic regurgitation grade was unchanged. Major in-hospital cardiovascular and cerebral events occurred in 8 patients (32%), including mortality in 5 patients (20%). Among 18 patients with device success surviving to discharge, no adverse events occurred within 30 days after leaving the hospital. Percutaneous implantation of the self-expanding CoreValve aortic valve prosthesis in high-risk patients with aortic stenosis with or without aortic regurgitation is feasible and, when successful, results in marked hemodynamic and clinical improvement.

Percutaneous Transcatheter Closure of Ventricular Septal Defects Using an Amplatz Device

We carried out an analysis of our initial experience with using an Amplatz device for percutaneous closure of ventricular septal defects in 15 patients. The patient's ages ranged in from 1 to 44 years. Seven were infants with heart failure. In 4 patients, the ventricular septal defect was located in the muscular portion of the ventricular septum; in 11 patients, it was in the perimembraneous portion. The mean size of the Amplatz device selected was 11.2 (3.0) mm. Successful device implantation was achieved in 12 patients. In the other 3, stable occlusion could not be achieved, and the device was retrieved without complications. Immediate complete closure occurred in 11 of the 12 patients who underwent successful implantation. No complications were observed, either immediately or during follow-up. After a mean follow-up period of 9.2 (3.6) months, all patients remained free of symptoms. Follow-up Doppler echocardiography demonstrated complete closure in all patients.

Predictors of Appropriate Defibrillator Therapy Among Patients with an Implantable Defibrillator That Delivers Cardiac Resynchronization Therapy

The purpose of this study was to determine predictors of appropriate implantable defibrillator (ICD) therapy among patients with heart failure who are treated with a cardiac resynchronization therapy-defibrillator (CRT-D). Patients enrolled in the Ventak CHF/Contak CD study were treated with a CRT-D device and were required to have NYHA class II-IV CHF, QRS duration > or = 120 msec, and a class I or II indication for an ICD. The study database was retrospectively analyzed during the 6-month postimplant period to identify predictors of appropriate ICD therapy. Five hundred and one of the 581 patients enrolled in the trial had successful device implantation and were included in this analysis. Patients were mostly male (83%), 66 +/- 11 years old, and had coronary artery disease (69%), a mean left ventricular ejection fraction (EF) = 0.22 +/- 0.07, and NYHA class II (33%), III (58%), or IV (9%) CHF symptoms. During 6 months of follow-up, 73 of 501 (14%) patients received an appropriate ICD therapy. Two independent predictors of appropriate therapy were identified: a history of a spontaneous, sustained ventricular arrhythmia (HR = 2.05; 95% CI = 1.31-3.20; P = 0.002) and NYHA class IV CHF (HR = 1.81; 95% CI = 1.10-2.96; P = 0.019). When patients with NYHA class II were excluded from analysis, a history of a sustained ventricular arrhythmia and the presence of NYHA class IV CHF symptoms remained as independent predictors of appropriate ICD therapy. In a select population of advanced heart failure patients receiving a CRT-D, NYHA class IV CHF was a powerful independent predictor of appropriate ICD therapy. Approximately one-quarter of the patients with NYHA class IV CHF who received a CRT-D device received an appropriate ICD therapy within 3 months after implant. Additional studies are needed to confirm an association between class IV CHF symptoms and an increased frequency of ICD shocks.

Urokinase‐immobilization suppresses inflammatory responses to polyurethane tubes implanted in rabbit muscles

Urokinase and plasmin appear to have antiinflammatory activity in some injury models, and urokinase immobilization has been clinically used to prevent thrombus formation in various implants, including intravenous indwelling catheters and subcutaneous drainage tubes. In the present study, polyurethane tubes were embedded in rabbit muscle for 3 months and the effect of urokinase immobilization on inflammatory responses to the implanted tubes was studied at 1 week, 1 month, and 3 months. Mononuclear leukocyte accumulation occurred around implanted polyurethane tubes and peaked after 1 month, but was reduced significantly by urokinase immobilization. The treatment also lessened as well as delayed eosinophil accumulation, but did not affect fibrosis caused by implanted tubes. These results indicate suppressive effects of urokinase immobilization on polyurethane-elicited inflammatory responses and suggest that an approach to develop persistently active urokinase immobilization is rational for successful long-term device implantation.

Primary transcatheter closure of postinfarction ventricular septal defects with the Amplatzer septal occluder- immediate results and up-to 5 years follow-up.

To report the periprocedural and long-term results of using the Amplatzer septal occluder for primary closure of post myocardial infarction ventricular septal defects. Transcatheter closure was considered in patients with significant left-to-right shunting and defect anatomy and location thought to be suitable for closure with such a device. From December 1999 until February 2005 eleven patients (9 males) aged 52-81 years (mean 67,9) underwent an attempted closure. The time from the onset of infarction to the procedure ranged between 2 days and 58 weeks (mean 15,4 weeks). There were three patients in an acute phase of infarction (three weeks or less). They were in critical condition and required inotropic and ventilatory support. Eight patients (all in a chronic infarction phase) were hemodynamically stable and in NYHA class III-IV (6 patients) or class II (2 patients). A successful device implantation occurred in all but one patient, in whom a 26 mm occluder pulled through a 16 mm defect on day 8 of infarction. An infarct exclusion surgery was successfully performed in this patient. In the remaining 10 patients, the defect size ranged 8-21 mm (mean 14,3), and the devices 11-30 mm (mean 19,3) were implanted. The procedure and screening time ranged 134-286 (mean 187,2) and 23-90 minutes (mean 43,6) respectively. The successful implantation did not clinically succeed in both patients with the acute septal rupture - they died 2 and 15 days after the procedure. In the eight patients in whom the procedure was performed late (3,5-56 weeks) after the infarction onset, the defect was either completely closed or the shunt was insignificant, and they improved dramatically. In the most recent follow-up from 1 to 62 months (mean 25,5), the patients have been alive and feeling well, and in NYHA I or II class. Primary transcatheter closure of postinfarction ventricular septal defects may be an alternative to surgery in patients with suitable anatomy and completed necrosis. In our experience, primary transcatheter closure of ventricular septal defects in patients who are in the acute phase of infarction does not improve their survival.

Transthoracic echocardiographic guidance of transcatheter atrial septal defect closure

This study examines the safety and efficacy of transthoracic echocardiographic (TTE) guidance of atrial septal defect (ASD) device closure. We evaluated 74 patients for TTE-guided ASD closure. Fifty-six patients had successful device implantation using TTE guidance. Twelve patients were referred for surgical ASD closure on the basis of TTE evaluation. Five patients with multiple ASDs or poor transthoracic acoustic windows had ASD device closure guided by transesophageal echocardiography (TEE).

On-line intracardiac echocardiography alone for Amplatzer Septal Occluder selection and device deployment in adult patients with atrial septal defect

Background: During the last few years, several different devices have been proposed for atrial septal defect (ASD) percutaneous closure. For the Amplatzer Septal Occluder (ASO) device, accurate balloon sizing is considered of paramount importance because the prosthesis waist has to be exactly adjusted to the defect diameter (±1 mm). In this study, we aimed to demonstrate the possibility of marked misinterpreting of the actual defect size using the balloon technique in patients with secundum ASD and to evaluate the accuracy of intracardiac echocardiography (ICE) measurements as a new method for selecting the size of ASO device. Methods: Between February 1999 and December 2000, 166 consecutive adult patients underwent percutaneous transvenous secundum ASD occlusion using the ASO device. In 124 patients (control group), ASD were closed by conventional methods. In 13 patients (pilot group), balloon pulling technique was used in size selection, whereas ICE was used on-line to monitor device placement and off-line to assess its possibilities for accurate quantitative measurements and qualitative evaluation. In 31 patients (study group), ICE was used as the sole imaging tool both for guiding device selection and monitoring the procedure. All patients underwent complete transthoracic echocardiographic study before discharge and during follow-up visits at 3 and 12 months. Results: Successful device implantation was accomplished in 163 of the 166 patients (98.2%). Short-term follow-up results were available in all eligible patients at least 3 months. Complete occlusion was demonstrated in 91.4% and 92.2% of patients in the control and pilot groups, respectively, increasing to 97.3% in the study group ( p<0.01 vs. both control and pilot groups). There were no significant differences in mean ASO diameters in the control and pilot groups (20±7.7 and 22±5.4 mm, respectively), whereas the mean size of the devices used in the study group was significantly larger (27.4±6.2 mm, p<0.01 vs. both control and pilot groups). In the pilot group, the underestimation effect of the balloon strategy was evident, with a mean 12.3% larger diameter required on ICE measurements. Moreover, a misalignment between the ASO and the atrial septum was seen on ICE in 9 of 13 patients of the pilot group, whereas good apposition of the ASO on the septum secundum was seen in all patients of the study group. Conclusion: ICE is a safe and effective method for selecting ASO size and continuous monitoring of the procedure. In contrast to the previously reported implantation procedure (device-to-defect ratio 1:1), a device 10–20% larger than invasively measured stretched defect diameter should be chosen and implanted on the basis of the ICE data.

Ancillary techniques to facilitate endovascular repair of aortic aneurysms

Purpose: The ability to treat abdominal aortoiliac aneurysms and thoracic aortic aneurysms may be limited by coexisting arterial disease. Device deployment may be impaired by occlusive disease and tortuosity of the arteries used to access the aneurysm or by suitability of the implantation sites. In this study we describe the auxiliary procedures performed to circumvent these obstacles and thereby enable endovascular aneurysm repair. Patients and Methods: Between January 1, 1993, and December 31, 1999, 390 patients treated for aneurysm of the aorta with endovascular devices were entered prospectively in a vascular registry. Fifty (12%) of the 390 patients required adjunctive surgical techniques to (1) create or extend the length of the proximal or distal device implantation site or (2) permit device navigation through diseased iliac arteries. Auxiliary techniques used to extend or enhance implantation sites were elephant trunk graft (n = 2), the construction of renovisceral bypass grafts (n = 1), and subclavian artery transposition (n = 2). Plication of the common iliac artery at its bifurcation was performed in conjunction with femorofemoral bypass graft in nine patients to allow preservation of pelvic circulation by avoiding internal iliac artery sacrifice. Construction of a bypass graft to transpose the internal iliac artery orifice was performed in one patient. The auxiliary techniques used to facilitate device navigation were iliac artery angioplasty or stenting (n = 8), external iliac artery endovascular endarterectomy or straightening (n = 14), endoluminal iliofemoral bypass conduit (n = 5), and the construction of an open iliofemoral bypass conduit (n = 8). Results: Successful deployment of the endovascular devices was achieved in 49 (98%) of 50 patients. Auxiliary techniques were successful in providing access for endovascular device deployment in all 35 patients (100%). Mean follow-up for techniques to facilitate device navigation is 26 months for endovascular procedures and 42 months for the open bypass graft construction patients; no occlusions were observed at this moment. There were five patients with incisional hematomas that did not necessitate intervention. Fourteen (94%) of 15 patients underwent successful device implantation after the auxiliary maneuvers to enhance implantation site. Mean follow-up for implantation site manipulation is 28 months. One of the subclavian transpositions had a new onset of Horner's syndrome, two of nine patients who had common iliac artery ligated had retroperitoneal hematomas that did not necessitate interventions, and no colon ischemia was seen. The patient who underwent nonanatomic bypass grafting of viscero-renal arteries had a retroperitoneal hematoma that necessitated reexploration. Conclusions: Significant coexisting arterial disease may be encountered in patients with aortic or iliac aneurysms. Identification of coexisting arterial diseases is essential to help tailor the appropriate supplemental surgical procedure to allow the performance of endovascular aneurysm repair in patients who would otherwise require open surgical repair. (J Vasc Surg 2001;34:69-75.)

Transvenous closure of moderate and large secundum atrial septal defects in adults using the Amplatzer septal occluder.

The aim was to determine the feasibility of using the Amplatzer septal occluder for closure of moderate and large secundum atrial septal defects in adults. Fifty patients aged 16-76 years (mean +/- SD, 40 +/- 15.5), underwent successful device implantation. Flow ratios of 1.4-8.5 (mean +/- SD, 2.6 +/- 1.6) were calculated. The defects were: centrally placed (n = 31), antero-superior with partial or total deficiency of aortic rim (n = 19), multiple (n = 3) and with aneurysmal septum (n = 23). They measured 4-25 mm (median 14) on echocardiography and balloon sized 7-31 mm (median 19.5). Devices of 7-34 mm (median 20) were implanted. Patient follow up for 1 month (50/50 patients), 3 months (40/50) and 12 months (13/50), achieved respective rates of 90%, 92% and 98% of complete occlusion. In one patient a transient atrioventricular block (2:1) developed, and one had a transient STT elevation. One female had an episode of 30 min loss of vision over the lateral aspect of the left eye 3 months after implantation. In conclusion, transvenous occlusion of secundum atrial septal defects with the Amplatzer septal occluder in adults is safe, and can be performed without significant complications. Large defects, defects with a very deficient or absent aortic rim, defects with an aneurysmal septum as well as some multiple defects can be closed with an almost 100% early complete occlusion rate. This makes the procedure an alternative to surgery for selected adult patients.

Quantitative Changes In T-Cell Populations After Left Ventricular Assist Device Implantation

Background—Left ventricular assist devices (LVADs) are currently being evaluated as permanent therapy for end-stage heart failure. Because life-threatening infections limit successful long-term device implantation, we investigated the relationship between quantitative T-cell defects in LVAD recipients and CD95-mediated T-cell apoptosis.Methods and Results—Immunological studies were performed in NYHA class IV patients awaiting cardiac transplantation who received either a TCI Heartmate left ventricular assist device (LVAD) or medical management. Fluorochrome-labeled Mabs were used in T-cell phenotypic analyses. T-cell apoptosis was measured by annexin V binding of T cells cultured in medium for 24 hours. Circulating serum levels of soluble CD95 were measured by ELISA. LVAD recipients had a relative lymphopenia and reduction in CD4 T-cell levels compared with NYHA class IV heart failure controls. These observations were confirmed in a longitudinal study in LVAD recipients, which showed that device implantation was accompanied by progressive and sustained reductions in circulating CD4 T-cell levels. These abnormalities in LVAD recipients were accompanied by increased levels of circulating soluble CD95 and by excessive CD4 and CD8 T-cell apoptosis. Susceptibility to induction of apoptosis was &gt;2-fold greater for CD4 T cells than for CD8 T cells.Conclusions—These results suggest that the reduction in CD4 T-cell levels accompanying LVAD implantation is a consequence of an augmented pathway of CD95-mediated apoptosis. The clinical consequences of these abnormalities may include increased prevalence of systemic infections.

Quantitative changes in T-cell populations after left ventricular assist device implantation: relationship to T-cell apoptosis and soluble CD95.

Left ventricular assist devices (LVADs) are currently being evaluated as permanent therapy for end-stage heart failure. Because life-threatening infections limit successful long-term device implantation, we investigated the relationship between quantitative T-cell defects in LVAD recipients and CD95-mediated T-cell apoptosis. Immunological studies were performed in NYHA class IV patients awaiting cardiac transplantation who received either a TCI Heartmate left ventricular assist device (LVAD) or medical management. Fluorochrome-labeled Mabs were used in T-cell phenotypic analyses. T-cell apoptosis was measured by annexin V binding of T cells cultured in medium for 24 hours. Circulating serum levels of soluble CD95 were measured by ELISA. LVAD recipients had a relative lymphopenia and reduction in CD4 T-cell levels compared with NYHA class IV heart failure controls. These observations were confirmed in a longitudinal study in LVAD recipients, which showed that device implantation was accompanied by progressive and sustained reductions in circulating CD4 T-cell levels. These abnormalities in LVAD recipients were accompanied by increased levels of circulating soluble CD95 and by excessive CD4 and CD8 T-cell apoptosis. Susceptibility to induction of apoptosis was >2-fold greater for CD4 T cells than for CD8 T cells. These results suggest that the reduction in CD4 T-cell levels accompanying LVAD implantation is a consequence of an augmented pathway of CD95-mediated apoptosis. The clinical consequences of these abnormalities may include increased prevalence of systemic infections.

Activation-induced T-cell death and immune dysfunction after implantation of left-ventricular assist de vice

Cardiac transplantation is a limited option for end-stage heart failure because of the shortage of donor organs. Left-ventricular assist devices (LVADs) are currently under investigation as permanent therapy for end-stage heart failure, but long-term successful device implantation is limited because of a high rate of serious infections. To examine the relation between LVAD-related infection and host immunity, we investigated immune responses in LVAD recipients. We compared the rate of candidal infection in 78 patients with New York Heart Association class IV heart failure who received either an LVAD (n=40) or medical management (controls, n=38). Fluorochrome-labelled monoclonal antibodies were used in analyses of T-cell phenotype. Analysis of T-cell function included intradermal responses to recall antigens and proliferative responses after stimulation by phytohaemagglutinin, monoclonal antibodies to CD3, and mixed lymphocyte culture. We measured T-cell apoptosis in vivo by annexin V binding, and confirmed the result by assessment of DNA fragmentation. Activation-induced T-cell death was measured after T-cell stimulation with antibodies to CD3. All immunological tests were done at least 1 month after LVAD implantation. Between-group comparisons were by Kaplan-Meier actuarial analysis and Student's t test. By 3 months after implantation of LVAD, the risk of developing candidal infection was 28% in LVAD recipients, compared with 3% in controls (p=0.003). LVAD recipients had cutaneous anergy to recall antigens and lower (<70%) T-cell proliferative responses than controls after activation via the T-cell receptor complex (p<0.001). T cells from LVAD recipients had higher surface expression of CD95 (Fas) (p<0.001) and a higher rate of spontaneous apoptosis (p<0.001) than controls. Moreover, after stimulation with antibodies to CD3, CD4 T-cell death increased by 3.2-fold in LVAD recipients compared with only 1.2-fold in controls (p<0.05). LVAD implantation results in an aberrant state of T-cell activation, heightened susceptibility of CD4 T cells to activation-induced cell death, progressive defects in cellular immunity, and increased risk of opportunistic infection.

Atrial septal defect occlusion with the buttoned device (a multi-institutional U.S. trial)

A clinical trial was conducted of the buttoned device for transcatheter closure of ostium secundum atrial septal defect. Occlusion was attempted in 57 patients aged 1 to 62 years (median 5). The procedure was abandoned in 7 patients after 1 or more unsuccessful attempts, and devices were released in 50 patients. Urgent surgical retrieval was necessary in 4 patients because of unstable device position: 3 devices “unbuttoned,” with migration of the counteroccluder to the pulmonary artery or inferior vena cava, and 1 intact device embolized to the main pulmonary artery. All patients remained stable and underwent successful operation. Successful device implantation was therefore achieved in 46 patients, with immediate reduction in Qp Qs from 1.8 ± 0.6 to 1.1 ± 0.2 (mean ± SD, p < 0.0001). At most recent follow-up (1 to 20 months), 45 of 46 patients (98%) have no shunt or a trivial residual shunt. The prevalence of residual shunts declined from 65% at 1 month to 19% at 12 months after the occlusion procedure (p < 0.0001). Complications included unbuttoning of a fourth device, transient tricuspid regurgitation in 2 patients, and transient mitral regurgitation in 2 patients. An episode of asymptomatic atrial flutter was noted in a 46-year-old patient which may have been related to device implantation, but which has not recurred. There have been no cases of endocarditis or thromboembolism in 350 patient-months of follow-up. The buttoned device provided effective closure of the atrial septal defect in 45 of 57 patients (79%) in whom implantation was attempted and in 45 of 46 patients (98%) in whom device implantation was successfully accomplished. Unbuttoning remains the major complication of the procedure; increased operator experience and design modifications to the device may reduce the frequency of this problem in the future.

Experience with 205 procedures of transcatheter closure of ductus arteriosus in 182 patients, with special reference to residual shunts and long-term follow-up

Between December 1987 and September 1991, 205 nonsurgical procedures for closure of patent ductus arteriosus were attempted in 182 infants, children, and young adults with use of the Rashkind double-disc ductal occluding device. The patients' ages ranged from 8 months to 26 years (median 5 years) with 18 aged less than 2 years. Their weights ranged from 7.4 to 55 kg (median 16 kg); in patients aged less than 2 years the mean weight was 10.2 +/- 1.5 kg, and in those aged more than 2 years mean weight was 19.5 +/- 9.6 kg. Successful occluder device implantation was achieved in 174 patients (96%) at the initial attempt. Device embolization to a pulmonary artery occurred in six patients; two of these devices were retrieved by grabber catheter and four at operation, all without adverse sequelae; there were two other technical failures. Follow-up studies included two-dimensional Doppler echocardiography with color flow mapping. The 6-week follow-up study revealed a small residual shunt in 27% (46/169) of patients. At the 6-month follow-up study, 22% (37/167) of the patients had a small residual shunt; this prevalence was 17% (24/145) in ducts with a narrowest diameter of less than 6 mm, and 59% (13/22) in ducts greater than 6 mm. Immediately after implantation of the occluder device and throughout the follow-up period, the mean narrowest ductal diameter of ducts with residual shunts was significantly larger than that of ducts in which total occlusion was achieved (range of p < 0.01 to 0.001). The use of the 17 mm occluder device, however, was significantly associated with an increased prevalence of residual shunt only immediately after implantation (p < 0.01). Implantation of a second occluder device was attempted in 21 patients with residual patent ductus together with a continuous murmur at the 6-month follow-up; embolization of one device to a pulmonary artery occurred immediately but it was retrieved by grabber catheter and another device was successfully implanted 1 month later. All 21 patients were seen for 6-month follow-up study, when only one (5%) had a small residual shunt that was subsequently successfully closed by the insertion of a third occluder device. Thus, after successful implantation of one or more occluder devices, complete closure of the ductus was achieved in 90% of all patients seen to date for their 6-month follow-up study. One patient had limited hemolysis. The maximum follow-up period is 50 months. These results confirm the efficacy, with low morbidity and no mortality, of the use of the Rashkind occluder device for nonsurgical closure of patent ductus arteriosus, especially in those with smaller diameters.