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Surgical anatomy of atrioventricular septal defect
Iki Adachi1, Hideki Uemura, Karen P McCarthy
1Cardiac Morphology Unit, National Heart & Lung Institute, Imperial College London, London, United Kingdom.
Insights
Atrioventricular septal defects feature a common atrioventricular junction and a 5-leaflet valve. Understanding the specific cardiac anatomy is crucial for successful surgical intervention in these complex congenital heart conditions.
Area of Science:
- Cardiology
- Congenital Heart Disease
- Cardiac Anatomy
Background:
- Atrioventricular septal defects (AVSD) encompass a spectrum of cardiac malformations.
- A key feature is a common atrioventricular junction with an abnormal valve.
- These defects lead to characteristic anatomical variations impacting cardiac function.
Purpose of the Study:
- To delineate the anatomical variations within atrioventricular septal defects.
- To emphasize the common anatomical features despite the spectrum of malformations.
- To highlight the importance of understanding cardiac morphology for surgical planning.
Main Methods:
- This is a review article.
- The study describes the anatomical spectrum of AVSD.
- It focuses on the characteristic features and variations in morphology.
Main Results:
- Hearts with AVSD share a common atrioventricular junction and a 5-leaflet valve.
- Lack of septation causes inlet-outlet disproportion.
- Bridging leaflet-septal relationships dictate shunting, outflow obstruction, and AV node position.
Conclusions:
- Understanding the fundamental cardiac morphology in AVSD is essential for surgical success.
- Recognizing the relationship between bridging leaflets and septal structures is key.
- Accurate anatomical assessment facilitates effective management of these congenital heart defects.
Abstract:
This review aims to describe the anatomic spectrum of hearts classified with the collective term atrioventricular septal defect. Despite their anatomical variety, hearts with the stigmata of atrioventricular septal defect share the characteristic feature of a common atrioventricular junction guarded by a 5-leaflet valve. The lack of normal atrioventricular septation makes the aorta un-wedged, resulting in an elongated outlet length on the left ventricular surface (known as inlet-outlet disproportion). The major determinant of anatomic variations is the relationship of the bridging leaflets to the septal structures. This important relationship determines not only the level of intracardiac shunting (interatrial only, interventricular only, or both) but also the propensity for left ventricular outflow tract obstruction. Furthermore, the location of the atrioventricular node, which is posteroinferiorly displaced from the tip of the triangle of Koch, is also affected by this relationship. Understanding the cardiac anatomy in this malformation is an absolute prerequisite for successful surgery, and should be facilitated by recognizing the fundamental nature of the morphology.
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