Skeletal muscle ventricles: Full versus half aortic ligation

Background: Skeletal muscle ventricles have been shown to provide effective aortic diastolic counterpulsation in an experimental model. Construction h as included full ligation of the thoracic aorta. The authors sought to dete rmine if these muscle pumps could function effectively without fully ligati ng the aorta. Methods: Skeletal muscle ventricles were constructed in two g roups of dogs. Group 1 had their aortas fully ligated (n = 10) while group 2 had their aortas narrowed by 50% (n = 10). The animals were followed for 10 weeks. Results: There was no significant difference in femoral diastolic augmentation at implant or at 10 weeks (19.1% +/- 9.9% in group 1 [full li gation] versus 16.3% +/- 10.2% in group 2 [half ligation] p = 0.502). Survi val to 10 weeks was significantly better in group 1 (full ligation). Nine o f 10 animals in this group survived versus 4 of 10 in group 2 (p = 0.019). Two animals survived in the half ligation group with effective augmentation and without thrombus formation. Conclusion: Both models produce effective diastolic counterpulsation. Survival was decreased in this model using half ligation, and survival without complication was observed in 2 of 10 animal s. Currently the overall results are better with the full aortic ligation m odel. However, design modifications will probably result in an effective mo del of diastolic counterpulsation without full aortic ligation.