Creation and enlargement of atrial defects in congenital heart disease

Left atrial decompression as a palliative minimally invasive treatment for congestive heart failure caused by myxomatous mitral valve disease in dogs: 17 cases (2018-2019)

OBJECTIVE

To determine whether left atrial decompression (LAD) would reduce left atrial pressure (LAP) in dogs with advanced myxomatous mitral valve disease (MMVD) and left-sided congestive heart failure (CHF) and to describe the LAD procedure and hemodynamic alterations and complications.

ANIMALS

17 dogs with advanced MMVD and left-sided CHF that underwent LAD.

PROCEDURES

The medical record database was retrospectively reviewed for all LAD procedures attempted in dogs with MMVD and left-sided CHF between October 2018 and June 2019. Data were collected regarding signalment (age, breed, weight, and sex), clinical signs, treatment, physical examination findings, and diagnostic testing before and after LAD. Procedural data were also collected including approach, technique, hemodynamic data, complications, and outcome.

RESULTS

18 LAD procedures performed in 17 patients were identified. Dogs ranged in age from 7.5 to 16 years old (median, 11 years) and ranged in body weight from 2.9 to 11.6 kg (6.4 to 25.5 lb) with a median body weight of 7.0 kg (15.4 lb). Minimally invasive creation of an atrial septal defect for the purpose of LAD was successful in all dogs without any intraoperative deaths. Before LAD, mean LAP was elevated and ranged from 8 to 32 mm Hg with a median value of 14 mm Hg (reference value, < 10 mm Hg). Following LAD, there was a significant decrease in mean LAP (median decrease of 6 mm Hg [range, 1 to 15 mm Hg]). Survival time following LAD ranged from 0 to 478 days (median, 195 days).

CONCLUSIONS AND CLINICAL RELEVANCE

For dogs with advanced MMVD and left-sided CHF, LAD resulted in an immediate and substantial reduction in LAP.

Cardiovascular anatomy in children with bidirectional Glenn anastomosis, regarding the transcatheter Fontan completion

BACKGROUND

Transcatheter stent-secured completion of total cavopulmonary connection (TCPC) after surgical preparations during the Glenn anastomosis procedure has been reported, but complications from this approach have precluded its clinical acceptance.

AIMS

To analyse cardiovascular morphology and dimensions in children with bidirectional Glenn anastomosis, regarding the optimal device design for transcatheter Fontan completion without special surgical "preconditionings".

METHODS

We retrospectively analysed 60 thoracic computed tomography and magnetic resonance angiograms performed in patients with a median age of 4.1 years (range: 1.8-17.1 years). Additionally, we simulated TCPC completion using different intra-atrial stent-grafts in a three-dimensional model of the representative anatomy, and performed calculations to determine the optimal stent-graft dimensions, using measured distances.

RESULTS

Two types of cardiovascular arrangement were identified: left atrium interposing between the right pulmonary artery (RPA) and inferior vena cava, with the right upper pulmonary vein (RUPV) orifice close to the intercaval axis (65%); and intercaval axis traversing only the right(-sided) atrial cavity, with the RUPV located posterior to the atrial wall (35%). In the total population, the shortest median RPA-to-atrial wall distance was 1.9mm (range: 0.6-13.8mm), while the mean intra-atrial distance along the intercaval axis was 50.1±11.2mm. Regardless of the arrangement, 83% of all patients required a deviation of at least 5.9±2.4mm (range: 1.2-12.7mm) of the stent-graft centre at the RUPV level anteriorly to the intercaval axis to avoid covering or compressing this vein. Fixing the anterior deviation of the curved stent-graft centre at 10mm significantly decreased the range of bend angle per every given RUPV-RPA distance.

CONCLUSIONS

For both types of cardiovascular arrangement, after conventional bidirectional Glenn anastomosis, the intra-atrial curved stent-graft seemed most suitable for achieving uncomplicated TCPC completion percutaneously without previous surgical "preconditionings" in the majority of children. Experimental study is necessary to validate this conclusion.

Middle-term results of trans-catheter creation of atrial communication in patients receiving mechanical circulatory support

OBJECTIVE

To describe our center's middle-term outcomes following trans-catheter creation of atrial communication (ASD) in patients on mechanical circulatory support.

BACKGROUND

Trans-catheter creation of an ASD in patients on mechanical circulatory support is an adjuvant therapy to reduce left atrial pressure and associated morbidity. Data on middle term outcomes following this procedure, specifically in regards to the fate of the ASD, are limited.

METHODS

Retrospective observational study of consecutive children and adults undergoing trans-catheter creation of an atrial septal communication between 1/1/2006 and 5/1/2014, reviewing their baseline characteristics, procedural details, and data from follow-up.

RESULTS

Over the study period, 37/227 (16%) subjects undergoing veno-arterial extra-corporeal membrane oxygenation (VA-ECMO) underwent trans-catheter creation of an atrial communication. Mortality on VA-ECMO support in this subgroup was 19%, with an additional 24% transitioning to ventricular assist device. Of the 57% who survived to separation from VA-ECMO, 16/21 (76%) had residual atrial communications. 56% of these underwent closure procedures.

CONCLUSIONS

Following trans-catheter creation of ASD, a residual ASD is present in the majority of assessable survivors and represents a potential volume overload and/or right to left shunt that may need to be addressed.

Restrictive tunnel patent foramen ovale and left atrial hypertension in single-ventricle physiology: implications for stent placement across the atrial septum

Our objective is to describe our approach to the management of patients with single-ventricle physiology and restrictive tunnel patent foramen ovale (TPFO) with unfavorable atrial septal morphology. We describe a series of five patients with single-ventricle physiology and restrictive TPFO and our experience with radiofrequency perforation (RFP), static balloon atrial septostomy (BAS), and stent implantation to create an alternative pathway for left atrial decompression. Between July 4, 2006, and July 10, 2007, five patients with single-ventricle physiology and restrictive TPFO were brought to the cardiac catheterization laboratory for decompression of a hypertensive left atrium. Four of five patients underwent RFP followed by static BAS and stent implantation across the newly created atrial communication. One patient had a stent placed across an existing TPFO. Unfortunately, stable stent position was not achieved in this case, and the patient required open atrial septectomy. In patients with single-ventricle physiology and a restrictive TPFO associated with left atrial hypertension, stent placement across the existing defect can result in unstable stent position. Using a RFP wire to create a new defect in the septum primum allows stable stent deployment across the atrial septum and achieves left atrial decompression.

Percutaneus double stent atrial septostomy

Graded balloon septostomy, bladed atrial septostomy, fenestrated Amplatzer devices and stent placement have been reported to obtain stable interatrial communications. We expose our favorable experience creating an interatrial septal defect, by the use of two stents concentrically placed. We think it can be a procedure to be taken into account whenever a wide interauricular septal orifice must be achieved.

New transcatheter techniques for creation or enlargement of atrial septal defects in infants with complex congenital heart disease

OBJECTIVES

To describe a series of 8 consecutive infants (5 with transposition of the great arteries [TGA] and 3 with hypoplastic left heart syndrome [HLHS]) who underwent nonconventional septostomy techniques.

BACKGROUND

For some complex congenital heart defects, an unrestrictive atrial septal defect (ASD) is essential to achieve an adequate cardiac output and/or systemic saturation. In some scenarios, the use of conventional septostomy techniques may be technically difficult, hazardous, and/or ineffective.

METHODS

Use of transhepatic approach, cutting balloons, and radiofrequency perforation with stenting of the atrial septum.

RESULTS

The size of the ASD and the oxygen saturation increased in all patients with no major complications. In those with TGA, the ASDs were considered to be of good size at the arterial switch operation. Two of the 3 patients with hybrid palliation for HLHS have developed some degree of obstruction within the interatrial stent over 2-3 months. At surgery, the stents were found to be secured within the septum with one showing significant fibrous ingrowth after uneventful removal. The other had some nonobstructive ingrowth.

CONCLUSIONS

Creation or enlargement of ASDs in infants using new nonconventional transcatheter techniques is feasible, safe, and effective, at least in the short-to-mid-term follow-up. Infants with TGA seem to benefit the most because the procedure results in satisfactory clinical stability for subsequent early surgical intervention. In infants with HLHS palliated by a hybrid approach, stent implantation to the atrial septum seems to buy enough time to bring them to the phase II safely despite progressive in-stent obstruction.

Decompression of the left atrium during extracorporeal membrane oxygenation using a transseptal cannula incorporated into the circuit

OBJECTIVES

When extracorporeal membrane oxygenation (ECMO) is used in the setting of severe myocardial dysfunction, left ventricular end-diastolic and left atrial pressure can rise to extremely high levels. Decompression of the left atrium in this setting is essential for resolution of pulmonary edema and recovery of left ventricular function. We sought to evaluate whether adequate left atrial decompression can be achieved via percutaneous placement of a transseptal left atrial drain incorporated in the ECMO venous circuit.

DESIGN

Retrospective case series.

SETTING

Tertiary care center pediatric intensive care unit and cardiac catheterization laboratory.

PATIENTS

Seven patients (age 8 months to 28 yrs) with cardiac failure on venoarterial ECMO with left atrial hypertension.

INTERVENTIONS

All patients underwent left atrial decompression with transseptal puncture and placement of a drain (8- to 15-Fr) incorporated into the ECMO venous circuit. Catheterization and ECMO records and echocardiograms were reviewed, as were the clinical course and outcome for each patient.

MEASUREMENTS AND MAIN RESULTS

The median time from ECMO cannulation to left atrial decompression was 11 hrs. Average initial left atrial pressure was 31 mm Hg. Successful drain placement was achieved in seven patients with no major procedural complications. Echocardiographic improvement in left atrial dilation was achieved in five patients (71%). Inability to decompress the left atrium was fatal in two patients. Four patients were decannulated (57%), and three survived to hospital discharge (43%). Larger sheath size and higher flow rate correlated with a greater likelihood of success.

CONCLUSIONS

Adequate decompression of the left atrium can be achieved by transseptal placement of a left atrial drain incorporated into the ECMO circuit. This technique represents a reasonable alternative to blade or balloon atrial septostomy for patients requiring left atrial decompression.