Volume 10 Supplement 1
109 Antegrade percutaneous closure of membranous ventricular septal defect using X-Ray fused with MRI (XFM)
© Ratnayaka et al; licensee BioMed Central Ltd. 2008
Published: 22 October 2008
Catheter-based closure of ventricular septal defects (VSD) is technically demanding. It involves crossing the VSD retrograde (from the left to right ventricle), retrieving a guidewire from the right ventricle side, positioning a delivery sheath for the closure device into the left ventricular apex, and device deployment.
We used X-ray Fused with MRI (XFM) to localize the VSD and guide antegrade (right to left) catheter crossing. We hypothesized that XFM-guided antegrade VSD crossing would simplify the procedure and reduce fluoroscopy time and radiation exposure.
12 Yucatan miniswine (29–55 kg) with inherited perimembranous VSD underwent baseline MRI scanning to delineate VSD, ventricular cavities and outflow tracts, aortic valve and root (see Figure 1). These features of interest from end-diastolic MRI frames were "fused" with live X-ray using external fiducial markers for rigid-body registration.
We compared antegrade VSD crossing attempts, in random order, under conventional X-ray or XFM guidance. We also compared, in random order, antegrade XFM guided sheath delivery and conventional retrograde X-ray guided crossing, wire exchange, and sheath exchange. Finally we closed the VSD using appropriately sized Amplatzer Memranous VSD Occluder (courtesy of AGA Medical Corp).
In all twelve animals, XFM-guided antegrade crossing of the VSD (2–9 mm) was successful. Antegrade guidewire crossing was faster under XFM (38 ± 18 s) than under conventional X-ray (391 ± 325 s, mean difference 314 ± 328 s, p = 0.02)
Conventional XRAY/Retrograde Technique versus Novel XFM/Antegrade Technique
Conventional XRay Guided Retrograde Technique
Novel XFM Guided Antegrade Technique
Difference Between XFM vs XRAY
p value 2-tailed t test)
VSD crossing time
275 ± 161 s
132 ± 90 s
143 ± 199 s
p = 0.04
Sheath platform time
469 ± 170 s
97 ± 102 s
372 ± 221 s
p < 0.001
493 ± 184 s
180 ± 127 s
288 ± 229 s
p = 0.001
Radiation dose-area-product (DAP)
5318 ± 2261 mGm2
2433 ± 2381 mGm2
2885 ± 1862 mGm2
p < 0.001
XFM-guided antegrade catheter crossing and closure of perimembranous VSD was considerably easier, faster, and associated with reduced radiation compared with conventional techniques.
This article is published under license to BioMed Central Ltd.