Surgical treatment of aortic dissection with ringed intraluminal graft--late results and fate of the false lumen

Between April 1981 and March 1992, sixty-nine patients underwent surgery for aortic dissection in our hospital and affiliated hospitals. Of them, 48 patients who survived the operation were followed up 2 months to 11.8 years (mean: 4.6 years). We compared the fate of the false lumen and late results in the 31 patients who underwent ringed intraluminal graft (RIG group) and the 17 patients who underwent conventional graft replacement (GR group). To clarify the status and severity of the dissected aorta, we devised a scoring system (dissection score: DS) to evaluate the long-term changes in the diseased aorta after operation. Of 12 patients (25%) who died of late dissection-related complications, 10 were in the RIG group and 2 in the GR group. The actuarial survival at 5 years was 66 +/- 9% in the RIG group and 88 +/- 8% in the GR group. Late dissection-related events (dissection-related death, redissection, reoperation) were observed in 17 patients, 14 of whom belonged to the RIG group and 3 to the GR group. The dissection-related event-free survival at 5 years was 51 +/- 10% in the RIG group and 88 +/- 8% in the GR group. In 36 (75%) of the 48 patients, including 20 (65%) of the 31 patients in the RIG group and 16 (94%) of the 17 in the GR group (p < 0.05), it was possible to resect the primary intimal tear. The actuarial survival at 5 years was 76 +/- 8% for those 36 cases in which resection of the primary intimal tear was possible and 64 +/- 15% for those in which resection was not possible. The dissection-related event-free survival at 5 years was 72 +/- 8% in the former group and 33 +/- 15% in the latter. The dissection score (DS) decreased from a pre-operative value of 21.5 +/- 8.4 to 12.0 +/- 9.3 postoperatively (p < 0.001). A significant decrease in DS was observed both in the RIG group and the GR group, in the former from 22.1 +/- 7.2 to 13.1 +/- 9.3, and in the latter from 19.9 +/- 11.5 to 9.1 +/- 9.2 (p < 0.01). The DS for those whose primary intimal tear could be resected was significantly decreased postoperatively (pre-operative 20.6 +/- 8.9, post-operative 9.3 +/- 8.4; p < 0.001); but for those whose primary intimal tear could not be resected, there was no difference between the pre- and post-operative DS (pre-operative 23.4 +/- 7.3, post-operative 18.2 +/- 8.7). The percent reduction in DS (%R) was significantly greater in the former group than in the latter one (61% vs. 29%; p < 0.02). DS significantly decreased for those with no late dissection-related events (from 22.4 +/- 9.2 to 10.9 +/- 8.8; p < 0.001) while for those who presented with such events there was no difference between before and after the operation (pre-operative 19.0 +/- 5.7, post-operative 14.9 +/- 10.6). The %R in those with dissection-related events tended to be lower than that in those without such events (33% vs. 58%). Resection of primary intimal tear seemed to be important not only to improve operative results in patients with aortic dissection but also to improve late results. Depending on the site and size of the intimal tear, the ringed intraluminal graft insertion technique often makes intimal tear resection impossible. Indications for this surgical technique are thus quite limited.