The impact of dissection membrane motility on mid-term aortic remodelling after thoracic endovascular repair

Intramural hematoma in the proximal sealing zone of the thoracic endovascular aneurysm repair: frequency and safety in acute and subacute type B dissections

Introduction

To assess the outcomes after thoracic endovascular aneurysm repair (TEVAR) in the presence of intramural hematoma (IMH) in the proximal sealing zone.

Material and methods

Patient data were retrospectively extracted from the hospital records of patients treated with TEVAR for acute and chronic aortic dissection type B in one single center. The initial, preoperative, first postoperative, and last follow-up CT scans were evaluated in the aortic 3D multiplanar reformats and the centerline regarding IMH presence in the proximal sealing zone, anatomical preconditions, and the morphological TEVAR complications including migration and bird-beak. Groups with (IMH) and without IMH (no-IMH) were compared.

Results

Overall, 84 patients (IMH:42; no-IMH:42) were treated at the age of 63(55; 72) years, of whom 23/84 (27%), 34/84 (40%), and 27/84 (32%) were in the hyperacute, acute and subacute dissection phases, respectively. The bovine arch was found in 10/84(12%) and the type III arch was most common (43/84;51%). IMH maximum extent was found in zones 0, 1, 2, and 3 in 14/84 (17%), 17/84 (20%), 18/84 (21%), and 6/84 (7%), respectively. Sealing was achieved in zone II in 71/84 (85%) and LSA was revascularized in 66/84 (79%) of the overall cohort. Early mortality and paraplegia were 2/84 (2%) each; stroke rate was 3/84 (4%). During the 22 months median follow-up (22;4;43) no RTAD was observed. Migration ≥10 mm (IMH: 11/82; no-IMH: 10/82; P = 1.0) and bird-beaks (IMH: 10/82; no-IMH: 12/82; P = 0.8036) were comparable in both groups and accompanied by a low aorta related mortality (1/82) in both groups.

Conclusion

The presence of the IMH in the proximal TEVAR sealing zone is frequent and may not be relevant for the occurrence of the RTAD, stent-graft migration, or bird-beak formation.

Bare Stent Fracture After TEVAR With the Modified Restrictive Bare Stent (RBS) Technique in Type B Aortic Dissections

PURPOSE

The aim was to assess the mid-term aortic remodeling and bare-metal stent (BMS) integrity of the restricted bare stent (RBS) technique reconstruction in aortic dissections.

MATERIALS AND METHODS

This retrospective cohort study included prospectively collected patients treated with the modified RBS technique between 2017 and 2020. The preoperative, postoperative, and last follow-up computed tomographic (CT) scans were analyzed in the centerline at the mid-descending, celiac trunk (CeT), and the mid-abdominal levels for false lumen (FL) patency, aortic diameter, and true lumen (TL) diameter changes. Bare-metal stent integrity was assessed in the 3-dimensional multiplanar reformats.

RESULTS

The median follow-up of the cohort (n=17) was 26 (11, 45) months. The procedure was mainly performed with the Relay NBS endograft (15/17; 88%) + E-XL BMS (17/17; 100%). Postoperative mortality, paraplegia, stroke, renovisceral vessel loss, and type I and III endoleaks were not observed. BMS fractured in 6 patients (6/17; 36%), damaged the dissection flap in 4/17 (24%), and led to the reperfusion of the FL and re-interventions with TEVAR (4/17; 24%). Two patients without FL reperfusion showed stable CT follow-ups 13 and 17 months after the fracture diagnosis. The TL expansion was seen at all landmarks and peaked in the thoracic aorta (+10; 6, 15; p<0.001). The FL thrombosis after modified RBS was only relevant in the thoracic aorta (p<0.001) and at CeT (p=0.003). The aortic diameter was stable in the thoracic aorta and increased at distal landmarks (CeT [+5; 1, 10; p=0.001]; mid-abdominal [+3; 1, 5; p=0.004]).

CONCLUSION

The modified RBS technique could not stop aortic growth below the diaphragm and prevent new membrane rupture due to the fractures of the BMS and consecutive flap damage with the reperfusion of the FL.

CLINICAL IMPACT

The treatment of complicated type B aortic dissections with TEVAR has become a standard. Particularly, patients with true lumen collapse and malperfusion may benefit from a more aggressive treatment strategy including proximal TEVAR and distal bare-metal stent implantation to re-open the true lumen and to prevent distal stent-induced new entry. However, this study reports the challenges of this approach with a high rate of bare-metal stent fractures during the follow-up. The fractures that occurred at the site of vertical nitinol bridges led to the dissection membrane ruptures and the reperfusion of the false lumen with consecutive dilatation. A close follow-up is mandatory to detect this complication and to treat the patients with TEVAR extension.

Favorable Remodeling After TEVAR in Uncomplicated Acute and Subacute Type B Aortic Dissection in Comparison to Conservative Treatment: A Midterm Analysis

PURPOSE

The purpose of the study was to evaluate the midterm and long-term outcomes of patients who underwent thoracic endovascular aortic repair (TEVAR) procedure to treat an uncomplicated acute and subacute type B aortic dissection (uATBAD) with high risk for subsequent aortic complications compared with the group of patients who received a conservative treatment protocol during the same period.

MATERIALS AND METHODS

Between 2008 and 2019, 35 patients who had TEVAR due to uATBAD and those with conservative procedure (n=18) were included in a retrospective analysis and follow-up study. The primary endpoints were false lumen thrombosis/perfusion, true lumen diameter, and aortic dilatation. The aortic-related mortality, reintervention, and long-term survival were the secondary endpoints.

RESULTS

In the study period, 53 patients (22 females) with a mean age of 61.1±13 years were included. No 30-day and in-hospital mortality was recorded. Permanent neurological deficits occurred in 2 patients (5.7%). In the TEVAR group (n=35) and in a median follow-up period of 34 months, a significant reduction of maximum aortic and false lumen diameter as well as a significant increase of true lumen diameter were detected (p<0.001 each). Complete false lumen thrombosis increased from 6% preoperatively to 60% at follow-up. The median difference in aortic, false lumen, and true lumen diameter was -5 mm (interquartile range [IQR]=-28 to 8 mm), -11 mm (IQR=-53 to 10 mm), and 7 mm (IQR=-13 to 17 mm), respectively. In 3 patients (8.6%), a reintervention was needed. Two patients (1 aortic-related) died during follow-up. The estimated survival according to Kaplan-Meyer analysis was 94.1% after 3 years and 87.5% after 5 years. Similar to the TEVAR group, no 30-day or in-hospital mortality was recorded in the conservative group. During follow-up, 2 patients died and 5 patients underwent conversion-TEVAR (28%). In a median follow-up period of 26 months (range=150), a significant increase of maximum aortic diameter (p=0.006) and a tendency to augmentation of the false lumen (p=0.06) were noted. No significant reduction of the true lumen was seen.

CONCLUSIONS

Thoracic endovascular aortic repair in patients at high risk of subsequent aortic complications in uncomplicated acute and subacute type B aortic dissection is safe and is associated with favorable midterm outcomes regarding aortic remodeling.

CLINICAL IMPACT

In a retrospective, single center analysis of prospectively collected data with follow-up, we compared 35 patients with high-risk features who recieved TEVAR in acute and sub-acute uncomplicated type B aortic dissection to a control-group (n=18). The TEVAR group showed a significant positive remoduling (reduction of max. aortic and false lumen diameter and increase of true lumen diameter (p<0.001 each)) during follow-up with an estimated survival of 94.1% after 3 years and 87.5% after 5 years.

Longitudinal morphological changes of the aorta and the endograft position before and after distal stent graft-induced new entry in aortic dissections

OBJECTIVES

The aim of this study was to assess the endograft position and aortic geometry changes after thoracic endovascular aortic repair (TEVAR) and frozen elephant trunk (FET) in distal stent-induced new entry (dSINE) patients.

METHODS

In this retrospective cohort study, the baseline demographic and the follow-up data were extracted from the hospital records, and computed tomography scans of dSINE patients after TEVAR or FET between 2011 and 2021 were analysed regarding endograft oversizing, length and migration, taper ratio, aortic diameter at the endograft end, aortic elongation (thoracic inner and outer curvature), wedge apposition angle and tortuosity angle in the distal landing zone.

RESULTS

dSINE was found in 22/213 (10%) of TEVAR and 10/31 (32%) of FET patients. The total follow-up time was 45 (27; 59) months. TEVAR was mainly performed with Relay NBS endograft (77%) and FET with Evita open prosthesis (80%). Paraplegia and stroke rates were 3%. dSINE occurred 17 (7; 35) months post-TEVAR and was instantly treated in 18 patients (56%) or followed up for 21 (11; 34) months (n = 14). Migration [+5 mm (1; 11; P < 0.001)], birdbeak angle [+9° (0; 27; P = 0.039)] and aortic diameter +5 mm (1; 11; P < 0.001) increased after dSINE, whereas aortic elongation increased already before [+12 mm (0; 27; P = 0.015)] and peaked after dSINE [+30 mm (9; 38; P < 0.001)]. The aortic elongation was more pronounced in the outer aortic curvature before and after dSINE (before: P = 0.039, after: P = 0.024). Postoperative wedge apposition [17° (12; 20)] increased before dSINE [21° (16; 35; P < 0.001)] and peaked thereafter [31° (21; 40; P < 0.001)].

CONCLUSIONS

Aortic elongation may influence the endograft position and provoke TEVAR failure in the distal and proximal landing zones.