Perforated Balloon Catheter

a more clinically relevant time frame. Methods and Results. We used a perforated balloon (Wolinsky) catheter to inject retroviral vectorcontaining virions into rabbit aortas in vivo. The virions were injected within 1 minute. Aortas were removed 5-14 days after injection and analyzed for evidence of gene transfer. In initial studies, nine rabbits were injected with a vector expressing the 3-galactosidase gene, and nine rabbits were injected with either non-f-galactosidase-containing vectors or with a vehicle control. Histochemical staining of aortic tissues revealed blue (positive) cells in eight of nine experimental rabbits and six of nine controls. Because of the lack of specificity of the 3-galactosidase detection system, we adopted a polymerase chain reaction-based protocol in which oligonucleotide primers were used to amplify specific vector-related sequences from aortic tissue extracts. The polymerase chain reaction protocol, calibrated with standards containing known numbers of transduced cells, revealed low amounts of vector-related sequences in six of 12 vector-injected rabbits and in one of 13 controls (p<0.03). Comparison with standards indicated that fewer than 100 transduced cells were present in a 2-cm length of the injected aortic tissue. Conclusions. Although in vivo gene transfer through an infusion balloon catheter can be accomplished within 1 minute, the therapeutic use of this protocol is limited by the small number of cells that are transduced. (Circulation 1992;85:1110-1117)