Management of older single functioning ventricles with outlet obstruction due to a restricted "VSD" in double inlet left ventricle and in complex double outlet right ventricle

Optimized preoperative planning of double outlet right ventricle patients by 3D printing and virtual reality: a pilot study

OBJECTIVES

In complex double outlet right ventricle (DORV) patients, the optimal surgical approach may be difficult to assess based on conventional 2-dimensional (2D) ultrasound (US) and computed tomography (CT) imaging. The aim of this study is to assess the added value of 3-dimensional (3D) printed and 3D virtual reality (3D-VR) models of the heart used for surgical planning in DORV patients, supplementary to the gold standard 2D imaging modalities.

METHODS

Five patients with different DORV subtypes and high-quality CT scans were selected retrospectively. 3D prints and 3D-VR models were created. Twelve congenital cardiac surgeons and paediatric cardiologists, from 3 different hospitals, were shown 2D-CT first, after which they assessed the 3D print and 3D-VR models in random order. After each imaging method, a questionnaire was filled in on the visibility of essential structures and the surgical plan.

RESULTS

Spatial relationships were generally better visualized using 3D methods (3D printing/3D-VR) than in 2D. The feasibility of ventricular septum defect patch closure could be determined best using 3D-VR reconstructions (3D-VR 92%, 3D print 66% and US/CT 46%, P < 0.01). The percentage of proposed surgical plans corresponding to the performed surgical approach was 66% for plans based on US/CT, 78% for plans based on 3D printing and 80% for plans based on 3D-VR visualization.

CONCLUSIONS

This study shows that both 3D printing and 3D-VR have additional value for cardiac surgeons and cardiologists over 2D imaging, because of better visualization of spatial relationships. As a result, the proposed surgical plans based on the 3D visualizations matched the actual performed surgery to a greater extent.

Narrative review of assessing the surgical options for double outlet right ventricle

The individualized surgical approach in individuals with both arterial trunks arising from the morphologically right ventricle is dictated by the extreme morphological variability encountered in this setting, with each patient being unique. An individualized surgical approach has been designed to take account of the morphological variations, identifying the anatomy with the preoperative three-dimensional CT scan reconstruction. The key features have been considered the distance between tricuspid and pulmonary valves, the size and location of the interventricular communication, and the relationship between the outflow tracts. The surgical approach is tailored, whenever feasible, to create a connection between left ventricle and aorta, but primarily to achieve biventricular repair. Account has been taken of all available surgical options already reported in the literature, identifying the most suitable to provide the best outcomes for each unique morphology. To date, meaningful comparison between different reported surgical series has been difficult because of the marked variation of individual intracardiac morphology, and the lack of reports of specific surgical approaches for well-categorized groups of patients. Our approach, being tailored to the individual cardiac morphology, can be offered to any patient with this ventriculo-arterial connection. Given the difficulties of diagnosis, and the multiple therapeutic indications, very close collaboration between cardiologists and surgeons is indispensable for further progress in the understanding and management of this complex congenital cardiac lesion.

Hybrid approach to ventricular septal defect enlargement

The need for creation or enlargement of a ventricular septal defect (VSD) is a rare occurrence. It is most frequently required in patients with double-outlet right ventricle who develop restriction of a remote muscular VSD or obstruction of a perimembranous VSD secondary to atrioventricular (AV) valve attachments to the interventricular septum. Surgical and transcatheter options for VSD creation or enlargement are associated with several risks including heart block, AV valve injury, and perforation. We report the first description of a hybrid approach to VSD creation and enlargement in two patients.

Bulboventricular foramen enlargement: an alternative surgical approach

Bulboventricular foramen (BVF) enlargement is often required to enlarge a restrictive interventricular communication in patients with univentricular hearts (UVH) to prevent the development of systemic ventricular outflow tract obstruction (SVOTO). We describe an alternative surgical technique through the transected pulmonary artery without an atriotomy, ventriculotomy or aortotomy that was successfully performed in a patient with double inlet left ventricle (DILV) with malposed great arteries (MPGA) and a restrictive BVF.

Mid-Term Outcomes of a Modification of Extended Aortic Arch Anastomosis with Pulmonary Artery Banding in Single Ventricle Neonates with Hypoplastic Transverse Arch

PURPOSE

There is less certainty regarding the best strategy for treating neonates with functional single ventricle (SV) and hypoplastic aortic arch. We have applied a modified extended aortic arch anastomosis (EAAA) and main pulmonary artery banding (PAB) as an initial palliation in neonates with transverse arch hypoplasia and assessed the mid-term outcomes.

METHODS

In total, 10 neonates with functional SV and extensive hypoplasia or interruption of the arch underwent a modified EAAA (extended arch anastomosis with a subclavian flap) concomitant with main PAB through a thoracotomy without cardiopulmonary bypass. Patient age and weight ranged from 4 to 14 days and 2.3 to 3.8 kg, respectively.

RESULTS

There were no hospital deaths although there were two late deaths. Gradients across the arch were 0 to 7 mmHg at postoperative day 1 and no arch reoperations were required. Two patients required balloon aortoplasty. Nine underwent bidirectional cavopulmonary shunt and two of them needed concomitant Damus-Kaye-Stansel (DKS) anastomosis. Six have completed Fontan.

CONCLUSION

Our modification of EAAA with main PAB for SV neonates may benefit a certain population with transverse arch hypoplasia as an option to be considered. Patients with the potential for developing outflow obstruction may be best managed with an initial DKS-type palliation.

Understanding the morphology of the specialized conduction tissues in congenitally malformed hearts

To repair congenital heart defects by means of open heart surgery, the surgeon needs guidance about the location and distribution of the specialized conduction tissues, in order to avoid their direct damage and consequent conduction disturbances. This review addresses the historical steps of the morphological study of the conduction system in different types of heart defects, providing updated information about the subject.

Management of the single ventricle and potentially obstructive systemic ventricular outflow tract

Multi-stage palliation is the current management strategy for the treatment of children with various single ventricle (SV) cardiac malformations. The success of this strategy depends on the presence of favorable anatomic and hemodynamic criteria. Several SV anomalies have the potential of developing systemic ventricular outflow tract obstruction (SVOTO) that might be evident early on or progress later after palliative surgeries. SVOTO could result in ventricular hypertrophy, impaired diastolic function and subendocardial ischemia with subsequent deleterious effects on the SV and disturbance of some of those criteria for a successful multi-stage palliation strategy. Careful identification of SV patients at risk of developing SVOTO and proper planning of the optimal palliation sequence beginning at the 1st stage procedure are vital factors that would affect long-term outcomes in those patients. In the current review, we describe the morphology of SV patients with potential SVOTO risk, surgical procedures that address potential or present SVOTO, and optimal timing of those procedures within the multi-stage palliation chain. We attempt to provide a treatment algorithm for various patients taking into consideration their unique anatomic and physiologic characteristics.