Evaluierung einer neuen Hybrid-Technik zum Verschluss muskulärer Ventrikelseptumdefekte im chronischen Tiermodell

OBJECTIVE: Therapy for muscular ventricular septal defects beyond
the moderator band, especially in neonates and infants, has always
been challenging for both surgeons and cardiologists. Recently, we
established a patch closure hybrid therapy for muscular ventricular
septal defects. In this study, we evaluated it in a long-term
porcine model. METHODS: Thirteen minipigs underwent anterolateral
thoracotomy to expose the left ventricle. Muscular ventricular
septal defects were created under 2- and 3-dimensional
echocardiographic guidance with a 7.5-mm sharp punch instrument.
Closure of the defects was undertaken with our new patch system in
hybrid technique. Animals were observed for 3 months.
Echocardiographic evaluation and pathologic examination, including
immunohistochemical staining, were undertaken. RESULTS: Defects
were successfully created in 12 pigs and closed in 10 pigs. Seven
survived for 3 months. Residual shunting was noticed in 1 animal.
Neither left ventricular dysfunction nor relevant damage to the
valves could be detected. Pathologic examination showed complete
endothelialization of the patch and the nitinol anchors without
protruding parts of the system. Cellular organization was
proceeding. Immunohistochemical staining demonstrated endothelial
cells on the surface of the patch and fibromuscular cells around
the patch. CONCLUSION: Our hybrid therapy was efficacious in
closing muscular ventricular septal defects without impairment of
cardiac function. The patch system and nitinol anchors demonstrated
good integration into the septum. Further development of the system
for human application is already being undertaken