Gelseal (R) versus Gelweave (R) dacron prosthetic grafts in the descendingthoracic aorta: a two-year computed tomography scan follow-up study

Background: In the abdominal aorta, the use of knitted rather than woven da cron prostheses has shown an early and slow late dilation. The dilation of woven versus knitted dacron prostheses in the thoracic aortic position has not yet been investigated. Method: From 1992, 26 patients entered a prospec tive study: 13 Gelweave(R) and 12 Gelseal(R) prostheses (diameter 18-26 mm) were implanted in the descending thoracic aorta. Computed tomography (CT) scans without contrast-enhancement were performed 2 weeks, and 1 and 2 year s postoperatively, The full length of the grafts was scanned and the diamet er was measured in mm measured at a level outside the areas of intercostal artery reimplantation. Patient determinants analysed were age. hypertension and implantation diameter of the grafts. The Gelseal group had a mean age of 63.7 years and seven were males. The Gelweave group had a mean age of 67 .8 years and seven were males. Results: the mean implantation diameters wer e 19.6 +/- 1.7 mm and 22.0 +/- 2.7 mm (P = 0.02) for the Gelseal and Gelwea ve grafts, respectively. On the CT-scans at 2 weeks postoperatively, the di ameter had increased by 18.8 +/- 4.8% (P = 0.0001) in the Gelseal and by 5. 7 +/- 6.4% (P = 0.007) in the Gelweave grafts, This difference in diameter at 2 weeks between the two prostheses was significant (P < 0.00001). At 1 y ear the diameter had increased by 28.4 +/- 6.2% (P = 0.0001) and by 8.4 +/- 4.6% (P = 0.0003) for the Gelseal and Gelweave grafts, respectively, compa red with the implantation diameter, The increase in diameter between the po stoperative values at 2 weeks and those at 1 year was statistically signifi cant in the Gelseal grafts (P = 0.0002) but not in the Gelweave grafts (P = 0.56). At 2 years an increase in diameter by 31.4 +/- 6.2% (P = 0.0001) an d by 7.4 +/- 7.1% (P = 0.014) for the knitted and woven prosthetic grafts, respectively, was noted compared with the initial implantation diameter. Th e increase in diameter between the CT measurements at 2 weeks and those at 2 years was statistically significant in the Gelseal group (P = 0.001) but not in the Gelweave group (P = 0.86). The difference in this late increase in diameter between the two implanted grafts was also significant (P < 0.00 5). Age, hypertension and initial diameter did not appear to be significant determinants. Conclusion: In contrast to the Gelseal prosthesis in the des cending aorta. the Gelweave prosthesis does not show any late dilation. (C) 1999 The International Society for Cardiovascular Surgery. Published by El sevier Science Ltd. All rights reserved.