Summary
Background
Studies on intracardiac echocardiography for transcatheter closure of secundum atrial septal defect (ASD) only include ASDs ≤ 38 mm diameter without rim deficiency.
Aims
To assess transcatheter closure of complex ASDs under intracardiac echocardiography guidance.
Methods
Retrospective study from January 2006 to January 2012 in all consecutive adult patients referred to our centre for percutaneous device closure of ASD. Complex cases were defined as defect > 38 mm and/or defect with rim deficiency other than the anterior-superior rim.
Results
Transcatheter closure was performed in 93 consecutive adult patients (59 women) with a median age of 48 (18–88) years. Complex cases comprised 17 patients (18%) with a median age of 54 (20–81) years and a median weight of 58 (45–99) kg. Thirteen cases had one or more deficient rims other than the anterior-superior rim, whereas nine had an ASD size > 38 mm. Transcatheter closure was successful in 14 cases, whereas three cases failed (18%). Minor complications occurred in three patients (18%). All the other non-complex ASDs were successfully closed percutaneously. Among the 93 patients, rim deficiency other than the anterior-superior rim tended to be associated with failure of transcatheter closure ( P = 0.058).
Conclusion
Transcatheter closure of complex ASDs is safe and effective under intracardiac echocardiographic guidance.
Résumé
Contexte
Les études sur l’échographie intracardiaque dans la fermeture par cathétérisme interventionnel des communications interauriculaires ostium secundum incluent seulement les défauts septaux de diamètre ≤ 38 mm sans berges déficientes.
Objectif
Évaluer la fermeture par cathetérisme et sous par échographie intracardiaque des communications interauriculaires complexes.
Méthodes
Il s’agit d’une étude rétrospective entre janvier 2006 et 2012 incluant tous les patients adultes référés dans notre centre pour la fermeture par cathétérisme interventionnel d’une communication interauriculaire. Les défauts septaux complexes étaient définis par un diamètre > 38 mm et/ou une ou plusieurs berges déficientes autre que l’antéro-supérieure.
Résultats
La fermeture percutanée a été effectuée consécutivement chez 93 patients adultes (59 femmes) à l’âge médian de 48 (18–88) ans. Dix-sept patients (18 %) étaient des cas complexes avec un âge et un poids médian de 54 (20–81) ans et 58 (45–99) kg respectivement. Treize cas avaient une ou plusieurs berges déficientes autres que l’antéro-supérieure alors que 9 patients avaient un défaut septal > 38 mm de diamètre. La fermeture par cathétérisme a été efficace dans 14 cas et un échec dans 3 cas (18 %). Des complications mineures sont survenues chez 3 patients (18 %). Toutes les communications interauriculaires non complexes ont été fermées avec succès. Parmi les 93 patients, la déficience d’une berge autre que l’antéro-supérieure tendait à être associée à un échec de fermeture ( p = 0,058).
Conclusion
La fermeture par cathetérisme des communications interauriculaires complexes est efficace et non risquée avec l’échographie intracardiaque.
Background
Transcatheter closure under transoesophageal echocardiography (TEE) and intracardiac echocardiography (ICE) guidance has become an accepted alternative to surgical repair for most types of ostium secundum atrial septal defect (ASD) . The technique is commonly used in patients with a defect < 38 mm in diameter without deficient rims, and allows safe and effective ASD closure in 80–88% of unselected cases . However, TEE is associated with the need for general anaesthesia in the majority of the cases and may provide suboptimal imaging and measurement of the defect .
Despite the risk inherent to its invasive nature, with the need for an 8-French sheath venous access, ICE provides excellent real-time detailed images that can be invaluable in guiding certain cardiac interventions . For transcatheter ASD closure, this obviates the need for general anaesthesia and has become a safe monitoring technique, with decreased procedural time and radiation exposure compared with TEE . Moreover, ICE has been demonstrated to be more accurate than TEE for taking anatomical measurements and guiding implantation . However, most studies on ICE monitoring for transcatheter ASD closure also included cases of patent foramen ovale (PFO) , with the exception of one cost-effectiveness study , two studies comparing TEE and ICE and one report on children weighing < 15 kg . Moreover, in all the previously published studies on ICE monitoring, large ASDs (> 38 mm) and defects with deficient rims were excluded, whereas the feasibility of transcatheter closure under TEE monitoring has been reported in such cases . Consequently, the feasibility of ASD closure under ICE guidance in complex cases (> 38 mm and/or deficient rims) has not been demonstrated.
The aim of the present study was to assess the safety and effectiveness of ICE monitoring for transcatheter closure of secundum ASDs in an unselected patient population including complex cases with large (> 38 mm) ASDs and/or deficient rims.
Methods
Study population
Since 2006 in our institution, ICE has fully replaced TEE as a guiding imaging tool for transcatheter ASD closure in the adult population. Children still undergo ASD closure under general anaesthesia and TEE guidance because of their lack of cooperation, the need for an additional 8-French venous access and the extra cost of ICE that does not offset the cost of anaesthesia care in France. Hence, we retrospectively studied all consecutive adult patients referred to our centre for percutaneous device closure of ostium secundum ASD from January 2006 to January 2012. This retrospective study was approved by the local ethics committee.
Patients aged ≥ 18 years with a haemodynamically significant ostium secundum ASD were eligible for the ICE-guided procedure, including those with clinical signs of heart failure, significant arrhythmia or a Qp/Qs ratio > 1.5. In addition, transcatheter closure was proposed for patients with secundum ASDs presenting with a stroke or showing any evidence of paradoxical embolization, regardless of the haemodynamic significance. All patients with a PFO were excluded from the study. Three patients with Down’s syndrome had transcatheter closure under general anaesthesia and were also excluded.
Preintervention protocol and definition of complex cases
All patients had a physical examination, standard 12-lead electrocardiography (ECG), transthoracic echocardiography (TTE) and TEE. TTE and TEE included multiple views to assess the ASD number, position, diameter, rim adequacy and relationship with adjacent cardiac structures. The rim around the ASD was classified as adequate (≥ 5 mm) or deficient (< 5 mm) for the coronary sinus rim, the inferior-posterior rim (towards the inferior vena cava), the inferior rim (towards the atrioventricular valves), the posterior rim (towards the pulmonary veins) and the superior-posterior rim (towards the superior vena cava) . Although patients with rim deficiencies and those with large defects are generally contraindicated , we consider them for transcatheter closure in our institution, based on previous studies and our experience of successful closure in such complex cases with a modified implantation method .
Consequently, we defined a case as ‘complex’ when transcatheter closure was attempted in a patient usually referred for surgery : diameter of the defect > 38 mm (on precatheterization TEE and/or percatheterization ICE and/or after calibration with the sizing balloon) and/or any rim deficiency other than the anterior-superior rim, as it is well established that deficiency in the anterior-superior rim towards the aorta does not influence the success rate of transcatheter ASD closure .
Echocardiographical guidance
The ICE catheter was introduced via the femoral vein using an 8-French sheath (11-French up to March 2009). An Acuson AcuNav TM ultrasound catheter (Siemens Ultrasound, Mountain View, CA, USA) was used for imaging and echocardiography was performed with an Acuson Sequoia C512 (Siemens Ultrasound, Mountain View, CA, USA) by the same experienced echocardiographer (G.H.). The imaging technique for ICE in ASD closure has already been reported in detail . Briefly, the probe is advanced to the interatrial septum level and the catheter is manoeuvred to provide four standardized views: the ‘home view’, with the transducer towards the tricuspid valve; the septal view, with the transducer towards the interatrial septum to image the defect and the interatrial septum; a horizontal long-axis view or four-chamber view, with the transducer towards the superior vena cava (and the inferior vena cava by withdrawing the probe); and a perpendicular short-axis view, displaying the aortic valve in cross section (and the anterior-superior rim).
Device closure protocol
Interventional procedure
The protocol of device closure has been reported previously . Briefly, transcatheter closure was performed using venous access through the femoral vein under local anaesthesia. Patients received 100 IU/kg of heparin (maximum 5000 IU) and antibiotic prophylaxis (cefamandole: 50 mg/kg). All patients underwent right heart catheterization as a first step in the interventional procedure.
Atrial septal defect sizing method
Two perpendicular unstretched ASD diameters were measured by ICE. Balloon sizing of the defect was only performed for large (> 20 mm) or complex defects, with the Meditech balloon (Boston Scientific, Watertown, MA, USA). The sizing balloon was introduced over the guidewire, passed into the left atrium and inflated; it was gradually deflated until it passed across the ASD then it was passed through a sizing plate to determine the stretched diameter of the defect, which corresponded with the waist diameter of the balloon.
Device selection and implantation
The closure device was selected based on the type and size of the ASD. A size 2 mm greater than the stretched diameter device was generally chosen, except in cases with important discrepancies between the size of the defect on different views, where a device smaller than the largest measured diameter was implanted.
Three types of device were used: the Amplatzer Septal Occluder (ASO) (AGA Medical Corporation, Plymouth, MN, USA); the Amplatzer Cribriform Multi-Fenestrated Septal Occluder (ACSO) (AGA Medical Corporation, Plymouth, MN, USA); or the Cardia Intrasept ASD Occluder (Cardia Inc., Eagan, MN, USA).
The ASO was used for single or adjacent multiple defects, whereas the ACSO was used for distant multiple defects. The Cardia Intrasept ASD Occluder was only used in one single small ASD case. The adequate positioning of the device was assessed under simultaneous fluoroscopic guidance and ICE. Before and after release of the device, positioning and relationships with cardiac structures were studied on ICE. In cases with a large defect, additional transthoracic views were often obtained. The presence of a residual shunt was documented by Doppler flow imaging showing a left-to-right shunt across the interatrial septum; it was defined as trivial (< 1 mm jet width), small (1–2 mm), moderate (2–4 mm) or large (> 4 mm) .
When the conventional implantation technique failed, a modified implantation technique involving the sizing balloon was employed, based on our previously published work . Briefly, the sizing balloon (Meditech; Boston Scientific, Watertown, MA, USA) was advanced over a wire placed in the left or right superior pulmonary vein, and was inflated within the interatrial septum or sometimes even in the left atrium in order to use it as a rim to anchor the device. Thereafter, the Amplatzer device was fully deployed while the balloon was still inflated. Once the Amplatzer device was fully delivered with the inflated balloon between the left and right atrial disc, the balloon was slowly deflated. If this approach failed, we tried this modified implantation technique again, with delivery of the left atrial disc just outside the opening of the right superior pulmonary vein.
Follow-up and medical treatment
Patients were evaluated by clinical examination, ECG and TTE on the day after implantation. After discharge, follow-up ECG and TTE were performed 1 week, 1 month and 6 months after ASD closure. Further life-long follow-up was recommended, with ECG and TTE 1 year after ASD closure and every other year.
Acetylsalicylic acid (160 mg/day) was started after the procedure and maintained for 6 months after transcatheter closure. Patients with pre-existing anticoagulation therapy were maintained with the same treatment without additional antiplatelet therapy.
Statistical analyses
Data are expressed as mean ± standard deviation if normally distributed or as the median (range). Analyses were performed to compare complex and non-complex cases ( Table 1 ) and to identify the factors that could be associated with the occurrence of failure. Non-parametric two-sided tests were used to compare continuous data (Mann-Whitney test) and categorical data (Fisher’s exact test). For all two-tailed tests, a value of P < 0.05 was regarded as statistically significant. All analyses were performed using SPSS software, version 17.0 for Windows (SPSS Inc., Chicago, IL, USA).
