[Malformation of the atrioventricular valve in atrioventricular septal defects and methods of plastic reconstruction in children].

The authors studied the surgical anatomy of atrioventricular valves (AV) in defects of the atrioventricular septum (AVSD) in a group of 73 preparations of the heart. Evidence was provided of a continual spectrum of changes of the entire valvular apparatus from a common AV orifice (71.2%) to two-separate orifices (28.8%). In the defect with a common orifice the authors differentiated six grades of overlapping of the left-sided component of the anterior common cusp with the right ventricle. In 12.3% hearts the authors revealed stenosis of the left AV orifice, which was most frequently caused by a thickened valve with reduced mobility. In 19.2% hearts the authors found a potentially stenotic configuration of the left AV orifice. From the surgical aspect it was possible to divide AVSD into the complete, transitional or partial type. The results of the morphological investigation were used during correction of 121 patients with AVSD. Of those 54 suffered from the complete form, 10 from the transitional and 57 from the partial form. During correction the authors closed the defect by using one or two patches and they performed an aimed plastic operation of the AV valves. The plastic repair involved closure of the cleft of the septal cusp of the left AV orifice, commissuroplasty, suture of abnormal commissures and straightening of irregular margins of the valve. In eight patients the plastic operation could not be performed because of a potentially stenotic configuration. The early mortality rate was 7.5% in the partial and transitional form and 18.5% in the complete form. The results were adversely affected by an unfavourable anatomy of the left AV orifice with severe regurgitation. From the great variability of the anatomy of AV valves and the authors' clinical experience ensues the necessity of an exact surgical solution of AVSD with an aimed and individually modified reconstruction of AV valves.