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Ventriculo-arterial discordance: switching the morphologically left ventricle into the systemic circulation after 3
M H Helvind1, J F McCarthy, M Imamura
1Center for Pediatric and Congenital Heart Diseases, Cleveland Clinic Foundation, Ohio 44195, USA.
Insights
Restoring the left ventricle to the systemic circuit in patients with ventriculo-arterial discordance is feasible with preparatory pulmonary artery banding. However, this complex surgery carries risks, especially in older patients, and may necessitate timely cardiac transplantation.
Area of Science:
- Cardiovascular Surgery
- Pediatric Cardiology
- Congenital Heart Disease
Background:
- Ventriculo-arterial discordance often necessitates complex surgical interventions.
- The morphologically right ventricle may develop dysfunction when placed in the systemic circuit.
- Restoring the morphologically left ventricle to the systemic circuit is a complex surgical strategy.
Purpose of the Study:
- To evaluate a 4-year policy of systemic-left ventricle restoration in patients with ventriculo-arterial discordance.
- To assess the feasibility and risks of reconditioning a deconditioned left ventricle for systemic circulation.
- To determine the effectiveness of this approach in different patient groups.
Main Methods:
- Retrospective analysis of 29 patients (1993-1997) with ventriculo-arterial discordance.
- Patients underwent procedures like Senning, arterial switch, and Rastelli operations.
- Preparatory pulmonary artery banding was used in 17 patients to recondition the left ventricle.
Main Results:
- Pulmonary artery banding increased the left/right ventricular systolic pressure ratio from 0.48 to 0.95.
- Left ventricular mass increased significantly in patients undergoing serial MRI.
- No deaths occurred in Group I (ccTGA); Group II (failed atrial switch) had two deaths; Group III (late d-TGA) patients did well.
Conclusions:
- Late anatomical correction of ventriculo-arterial discordance is possible with relatively low risk.
- Sequential pulmonary banding can recondition the left ventricle but carries risks.
- Timely transplantation may be necessary for older patients with inadequate left ventricular reconditioning.
Objective:
To retrospectively examine a 4 year policy of restoring the morphologically left ventricle to the systemic circuit in patients presenting after 3 months of age with ventriculo-arterial discordance with or without associated atrio-ventricular discordance. This policy was stimulated by the known tendency of the morphologically right ventricle to develop dysfunction sooner or later when left in the systemic circuit. Such a policy dictates a more complex surgical approach and, at this point, it remains controversial whether or not the increased surgical complexity is warranted.
Methods:
From July 1, 1993 to March 31, 1997, a total of 29 patients were entered into a protocol for placement of the morphologically left ventricle into the systemic circuit. Three groups of patients were identified. Group I; congenitally corrected transposition in 14 patients -- were treated with either a Senning plus arterial switch operation or Senning plus Rastelli procedure. Group II; failed atrial switch procedure in 12 patients of which nine proceeded to arterial switch operation with Senning or Mustard takedown and atrial reseptation. Group III; D-transposition of the great vessels presenting more than 1 year after birth in three patients who underwent arterial switch operation alone. A deconditioned morphologically left ventricle required reconditioning by means of preparatory pulmonary artery banding in 17 of 29 patients. In the patients requiring pulmonary artery banding, an average of 2.1 pulmonary artery bandings was required to prepare the morphologically left ventricle for a systemic pressure workload.
Results:
In those patients with a deconditioned morphologically left ventricle requiring preparatory pulmonary artery banding, the mean ratio between the left ventricular and right ventricular systolic pressure increased from 0.48 to 0.95. The left ventricular mass increased from 46.6 to 81.8 g/m2 in five patients subjected to serial MRI measurement. Three patients failed the preparatory pulmonary artery banding and did not proceed to anatomical correction. Two subsequently died at a later time. In the patients proceeding to complete anatomical correction: group I -- there were no early or late deaths. Two patients required pacemaker implantation post-operatively. Group II -- there were two in-hospital deaths, one early due to intrapulmonary hemorrhage and one late, secondary to postoperative left ventricular failure with a stormy post-operative course requiring successful ECMO placement and weaning. These patients were 18 and 25 years old, respectively. One patient proceeded to cardiac transplantation 3 months after surgery due to ongoing morphologically left and right ventricular dysfunction. Group III -- all patients continue to do well.
Conclusions:
Late anatomic correction of ventriculo-arterial discordance with or without atrio-ventricular discordance can be performed at a relatively low risk. Reconditioning of the morphologically left ventricle can be achieved by sequential pulmonary banding but is not without risk. Failure to achieve adequate reconditioning of the morphologically left ventricle by pulmonary artery banding in the older patient probably increases the risk of non-survival and may be offset by timely transplantation. Longer follow-up and an assessment of the functional status of these patients is required to assess whether or not this complex surgical approach is indeed warranted.