[Single ventricle and related anomalies. Anatomic findings in 30 cases. Diagnostic and therapeutic implications (author's transl)].

Anatomic characteristics are studied in 30 cases of single ventricle and related anomalies. Cases are distributed into 6 groups according to: a) the derangement in the expansión of the atrioventricular canal towards the "bulbus cordis", which may be either defective (groups I, II and III) or excessive (groups IV and V), and b) the hypoplastic nature of the ventricular septum (group VI). The most important conclusions are: 1) An L-bulboventricular loop was found in 43.47% of the entire material; all of them pertained to groups I, II and III. 2) A normal position of the great arteries was uncommon, being encountered in 13.4% of the cases. An aorta situated anteriorly and to the left was present in 30.43% of the cases included in groups IV and V. 3) Obstructive anomalies of either outflow tract were discovered in 66.6% of the entire material, regardless of the type of bulboventricular loop. 4) The left atrioventricular orifice was found to be abnormally small in 56.66% of the total case material and in 88.23% of the cases pertaining to groups I, II and III. 5) A mitral atresia was encountered in two cases pertaining to groups I and II. The criteria which have been used to admit cases with this association of anomalies have been established in previous publications by one of the authors of the present study. 6) The changes in the spacial orientation of the leaflets of the right atrioventricular orifice in cases with an L-bulboventricular loop are attributed to the rotation of the heart around its longitudinal axis which takes place in cases with levocardia and mesocardia. 7) A preoperative study as accurate as possible is necessary in order to establish a rational approach to the surgical management of these patients.