Long-term safety and durability of percutaneous septal sinus shortening (The PS(3) System) in an ovine model.

OBJECTIVES: Chronic implants of the PS(3) system were conducted in an ovine model to assess durability and safety at up to 1 year follow-up. BACKGROUND: The long-term durability and safety of emerging percutaneous devices for functional mitral regurgitation remain largely unknown. METHODS: The PS(3) system (consisting of interatrial septal and great cardiac vein devices connected by an adjustable suture bridge) was placed in eight healthy adult sheep. The mitral annular septal-lateral dimension in systole (SLS) was acutely reduced by 15-20%. Animals were sacrificed at up to 12 months postimplant and characterized by intracardiac echocardiography, cardiac computed tomography (CT), and histopathology. In vivo forces exerted on the PS(3) bridge were measured by means of a novel load cell catheter. RESULTS: At 3, 6, and 12 months after implantation, intracardiac echocardiographic and CT showed the PS(3) systems to be intact without erosion and with overall sustained reductions in the SLS. Histopathologic assessment revealed each component correctly deployed in its respective target site without evidence of erosion, thrombus, or device fracture. The SLS was 26.5 +/- 1.7 mm preimplant, 22.0 +/- 1.4 mm post-PS(3) (17.0% reduction), and 22.0 +/- 2.1 mm at latest follow-up. Mean forces exerted on the bridge in vivo ranged from 1.16 N to 1.87 N. CONCLUSIONS: The PS(3) System demonstrated excellent biocompatibility without evidence of erosion, thrombosis, or perforation at up to one-year follow-up in this chronic healthy ovine model. Forces exerted in the PS(3) system were relatively modest and should contribute to the durability of the device.

Value of FDG positron emission tomography in conjunction with MR imaging for evaluating therapy response in patients with musculoskeletal sarcomas.

OBJECTIVE: The purpose of our study was to investigate the potential of FDG positron emission tomography (PET) to distinguish viable tumor from changes caused by therapy in areas with equivocal MR imaging findings in patients with musculoskeletal sarcomas. MATERIALS AND METHODS: We evaluated 12 patients (nine males, three females; age range, 9-56 years; mean age, 25 years) with a history of bone or soft-tissue sarcoma who had undergone various treatments (surgery, chemotherapy, radiation therapy, or a combination of treatments) and who presented with clinically suspected recurrent or residual tumor. All patients underwent gadopentetate dimeglumine-enhanced MR imaging and whole-body FDG PET. Imaging results were correlated with histologic findings or with clinical findings from long-term follow-up. RESULTS: In nine patients, MR imaging findings were equivocal in differentiating between posttherapeutic changes and tumor recurrence. FDG PET images showed increased uptake, suggestive of recurrent tumor, in five patients. These findings were confirmed by biopsy. Four patients showed no increased uptake on FDG PET and were closely monitored clinically. No tumor recurrence was found in these patients. One patient showed MR imaging findings suggestive of recurrent tumor that was confirmed on FDG PET and at histology. Two patients underwent a limb salvage procedure before MR imaging, but MR images were deemed inadequate for interpretation because of extensive metallic artifacts. FDG PET was helpful in evaluating these patients for tumor recurrence. CONCLUSION: FDG PET is a useful adjunct to MR imaging in distinguishing viable tumor from posttherapeutic changes in patients with bone and soft-tissue sarcomas.