Implantation sequence modification averts distal stent graft-induced new entry after endovascular repair of Stanford type B aortic dissection.

OBJECTIVE: This study investigated predisposing factors of distal stent graft-induced new entry (SINE). METHODS: Data from November 2006 to May 2012 were abstracted retrospectively from the records of 73 patients with complicated type B aortic dissection who had received stent graft treatment in our institution. Diameters of the true and false lumen, area and circumference of the true lumen, prestent and poststent oversize, taper, and mismatch ratio were recorded and analyzed to see if there were any significant differences between the SINE (n = 19) and non-SINE (n = 54) population and between those in whom the initial endograft was inserted from the proximal thoracic aorta (n = 49) or the distal thoracic aorta (n = 24). RESULTS: A distal-first sequence of stent graft deployment produced significantly fewer instances of distal SINE. The area oversizing ratio of the distal end of the stent graft was greater in the SINE vs non-SINE groups (3.76 ± 1.7 vs 2.63 ± 2.57; P = .002) and in the proximal-first vs distal-first deployment sequence groups (3.67 ± 2.57 vs 1.39 ± 0.90; P < .001). CONCLUSIONS: Minimizing the preprocedure distal oversizing ratio with a distal small graft-first procedure could reduce the risk of late distal SINE for Stanford type B aortic dissection. Furthermore, the area ratio is a potentially more sensitive modality for size assessment and prediction of distal SINE occurrence.

Reintervention for distal stent graft-induced new entry after endovascular repair with a stainless steel-based device in aortic dissection.

OBJECTIVE: Stent graft-induced new entry (SINE) has been increasingly observed after thoracic endovascular aortic repair (TEVAR) for aortic dissection. We investigated the mechanism of late distal SINE, prevention strategies, proper size selection of the stent graft, and implantation sequence. METHODS: From November 2006 to May 2011, 99 patients with aortic dissection underwent TEVAR with Zenith TX2 stent grafts (Cook, Bloomington, Ind) at our center. Among them, 27 distal SINEs were recognized. Eight of these patients with complicated distal SINE required intervention with new distal endografts, and all were enrolled for further analysis. RESULTS: Eight of the 27 patients with distal SINE underwent a secondary endograft procedure from February 2011 to July 2011. All were successfully treated without any complications or deaths. A high taper ratio (35%±11%) and excessive oversizing of the true lumen area at the distal stent level (293%±76%) were noted among these patients. CONCLUSIONS: The incidence of distal SINE seemed to be high; however, there were also low rates of death and complications after TEVAR for aortic dissection using stainless steel-based stent grafts. Complicated distal SINE can successfully be resolved by distal endograft implantation. Excessive oversizing of the distal stent graft, as measured by the true lumen area, may be a significant factor causing delayed distal SINE. Precise size selection is crucial for the distal end of the stent, especially for high taper ratio dissection pathology in which the implantation sequence of a distal small-sized stent graft first might be considered to prevent future distal SINE.

Clinical Outcomes of VasoRing Connector in Patients With Acute Type A Aortic Dissection.

BACKGROUND: Outcomes of acute type A aortic dissection repair may be improved when VasoRing connectors (VRC [Sunwei Technology, Taipei, Taiwan]) are used to facilitate aortic anastomosis. In the present study, we compared the results of acute type A aortic dissection repair using VRC and conventional suture technique. METHODS: A total of 68 patients who underwent acute type A aortic dissection repair by total arch replacement and antegrade frozen elephant trunk procedure at our institution were enrolled. Records of patients receiving aorta anastomosis with VRC (n = 33) and conventional suture (n = 35) were retrospectively compared. All the surgical results were collected and analyzed. RESULTS: The results showed that the VRC group exhibited significance in total operative time (326 ± 80 minutes versus 362 ± 34 minutes, p = 0.023), cardiopulmonary bypass time (97 ± 10 minutes versus 134 ± 15 minutes, p < 0.001), aortic cross-clamp time (97 ± 10 minutes versus 134 ± 15 minutes, p < 0.001), and circulatory arrest time (15 ± 4 minutes versus 50 ± 8 minutes, p < 0.001) compared with the suture group. Use of VRC for aortic anastomosis led to significantly less perioperative blood loss (442 ± 75 mL versus 849 ± 419 mL, p < 0.001) compared with conventional suture for aortic anastomosis There was no reoperation for postoperative bleeding in the VRC group whereas reoperation for postoperative bleeding occurred in 20% of the suture group (0% versus 20%, p = 0.011). Postoperative blood loss, amount of blood transfusion, and acute kidney injury requiring hemodialysis were also significantly less in the VRC group than the suture group. CONCLUSIONS: Use of VRC shortened operative time and improved bleeding control incorporating standard methods for aortic anastomoses during acute type A aortic dissection repair by total arch replacement and antegrade frozen elephant trunk procedure. Long-term follow-up and randomized comparison are needed to confirm VRC efficacy.

Factors Affecting Optimal Aortic Remodeling After Thoracic Endovascular Aortic Repair of Type B (IIIb) Aortic Dissection.

PURPOSE: The purpose of this study was to determine factors associated with entire aortic remodeling after thoracic endovascular aortic repair (TEVAR) in patients with type B dissection. MATERIALS AND METHODS: The patients with type B (IIIb) dissections who underwent TEVAR from 2006 to 2013 with minimum of 2 years of follow-up computed tomography data were retrospectively reviewed. Based on the status of false lumen remodeling of entire aorta, patients were divided into three groups: complete regression, total thrombosis, and inadequate regression with patent abdominal false lumen. RESULTS: A total of 90 patients (72 males, 18 females; mean age 56.6 ± 16.4 years) were included and divided into the complete regression (n = 22), total thrombosis (n = 18), and inadequate regression (n = 50) groups. Multivariate logistic regression analysis indicated that dissection extension to iliac arteries, increased preoperative number of dissection tear over abdominal aorta, and decreased preoperative abdominal aorta bifurcation true lumen ratio, as compared between the inadequate and complete regression groups, were associated with a persistent false lumen (odds ratio = 33.33, 2.304, and 0.021; all, p ≤ 0.012). Comparison of 6, 12, and 24 months postoperative data revealed no significant differences at any level, suggesting that the true lumen area ratio might not change after 6 months postoperatively. CONCLUSIONS: Increased preoperative numbers of dissection tear around the abdominal visceral branches, dissection extension to the iliac arteries, and decreased preoperative true lumen area ratio of abdominal aorta are predictive of entire aortic remodeling after TEVAR in patients with type B dissection. LEVEL OF EVIDENCE: III.

Factors predictive of distal stent graft-induced new entry after hybrid arch elephant trunk repair with stainless steel-based device in aortic dissection.

OBJECTIVES: Stent graft-induced new entry (SINE) has been increasingly observed after thoracic endovascular aortic repair of aortic dissection. We illustrate the possible mechanism by exploring predictive factors of late distal SINE after hybrid arch elephant trunk repair for aortic dissection. METHODS: From November 2006, to May 2011, 20 of 99 patients underwent hybrid arch repair using the elephant trunk graft as the proximal landing zone. After a mean follow-up period of 27.9 ± 12.0 months, 12 patients had late distal SINE events and the others were free of events. False lumen remodeling level was observed and maximal longitudinal diameter, average of longitudinal and transverse maximal diameter, circumference, and area of true lumen were analyzed for precise size selection of stent graft before and after the procedure. Taper ratio, true lumen:aorta ratio, prestent grafting oversizing ratio, poststent grafting oversizing ratio, and expansion mismatch ratio of distal true lumen were proposed and calculated for further evaluation of the mechanism of late distal SINE. RESULTS: Only the area oversizing ratio between true lumen and the distal selected stent graft at the presumed distal end of stent grafting was found as a significant predictive factor of SINE before procedure (4.00 ± 2.96 vs 1.98 ± 0.66 for SINE vs non-SINE, respectively; P = .031). The significant difference of the expansion mismatch ratio of true lumen between the 2 groups was found not only in the size measurement of mean diameter (1.48 ± 0.29 vs 1.22 ± 0.15; P = .039), but also in the area (2.39 ± 0.85 vs 1.58 ± 0.42; P = .031) and circumference (1.43 ± 0.27 vs 1.18 ± 0.14; P = .016) after stent grafting. CONCLUSIONS: We found that taper ratio is not an optimal criteria for stent graft size selection and distal oversizing calculated by true-lumen area is a significant factor causing delayed distal SINE. Use of the prestenting area oversizing ratio should be limited.