[Interventional approach to the treatment of aneurysms of the perimembranous ventricular septal defects].

Objectives: To explore applicable protocol for the positioning of ventricular septal defect (VSD) occluder and the selection of the device by retrospective analysis of transcatheter closure approach to the aneurysms of the perimembranous VSD.

Methods: Thirty-five cases of perimembranous VSD with septal aneurysm (19 males and 16 females) from May, 2004 to May, 2005 were included, with a mean age of 5.3 y and mean weight of 17.6 kg. Their angiographic and ultrasound data, and interventional processes were analyzed. Seven segments of the aneurysms were assessed: the diameter of the defect on the left ventricle, the diameter of the defect on the right ventricle, the thickness of ventricular septum, the distance from the farthest end of the aneurysm to the defect, the diameter of the widest part of the aneurysm and the distance between the two farthest orifices on the aneurysm.

Results: Sixteen cystiform aneurysms and nineteen tubiform ones were identified with left ventricular angiography. The diameters of the orifices of aneurysms and the diameters of the VSDs ranged from 1.5 mm to 4.1 mm and 2.7 mm to 11.9 mm, separately, with the mean of 2.9 mm and 4.3 mm. From the echocardiography, the distances of the rim of defect to the aortic valve ranged from 2.0 mm to 7.0 mm, with the mean of 4.3 mm. All the interventions were successfully done with symmetrical devices from 4 mm to 14 mm. The left disc of the device was positioned at the defect surface from the left ventricle in 29 cases, and was released at the left side of the orifice in 3 cases.

Conclusions: The positioning of the left disc is mostly determined by the condition for the correct formation of the right disc in the right ventricle after deploying. Generally the defect surface in the left ventricle is most ideal to release the left disc of the device. If the body of aneurysm was too long for the right disc to restore its configuration, the left disc should be released on the left side of the orifice. The selection of device size is determined by the placement of the left disc. When the left disc is to be released at the defect surface in the left ventricle, the device size should be equal to or 1 to 2 mm larger than the diameter of the defect on the left ventricle. When the left disc is to be deployed on the left side of an orifice, the device size should be equal to or 1 mm larger than the defect diameter on the left ventricle when there is a single orifice. In the case of multiple orifices, the minimal size of the device which can cover all the orifices should be selected.