Landing Zone Remodelling after Endovascular Repair of Dissected Descending Aorta

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.

False lumen patency status and outcomes after endovascular repair of uncomplicated chronic type B dissection

BACKGROUND

Thoracic endovascular aortic repair (TEVAR) remains a controversial treatment for uncomplicated chronic type B aortic dissection (cTBAD). This study was performed to investigate the postoperative outcomes of TEVAR, such as survival and reintervention, and the risk factors for prognoses.

METHODS

In total, 41 patients with uncomplicated cTBAD who underwent TEVAR from 2014 to 2021 were reviewed. The patients were divided into two groups: those with false lumen complete thrombosis (FLCT) and false lumen partial thrombosis (FLPT) based on computed tomography angiography (CTA) images. Kaplan-Meier analysis was performed to estimate survival and freedom from reintervention. Binary logistic analysis was performed to estimate risk factors for partial thrombosis.

RESULTS

During a mean follow-up of 31 (1-78) months, five deaths and six reinterventions had occurred at 5 years. By 1 week, thoracic FLCT had occurred in 23 (56.1%) patients and thoracic FLPT had occurred in 18 (43.9%). The rate of freedom from reintervention was significantly lower in the FLCT than in the FLPT group (p = 0.04). The 5-year survival rate of the two groups was not statistically significant (p = 0.14). Risk factors for thoracic FLPT were the distance between the re-entry site and the graft (p = 0.02) and the proximal oversizing ratio (p = 0.04).

CONCLUSIONS

TEVAR is an effective and safe treatment for uncomplicated cTBAD and has a low mortality rate. Thoracic FLCT is associated with less reintervention, but overall survival is not impacted by this difference. Patients treated with TEVAR without certain risk factors can have a good prognosis.

Mid- and long-term outcomes of thoracic endovascular aortic repair in acute and subacute uncomplicated type B aortic dissection

BACKGROUND

Uncomplicated type B aortic dissection (un-TBAD) has been managed conservatively with medical therapy to control the heart rate and blood pressure to limit disease progression, in addition to radiological follow-up. However, several trials and observational studies have investigated the use of thoracic endovascular aortic repair (TEVAR) in un-TBAD and suggested that TEVAR provides a survival benefit over medical therapy. Outcomes of TEVAR have also been linked with the timing of intervention.

AIMS

The scope of this review is to collate and summarize all the evidence in the literature on the mid- and long-term outcomes of TEVAR in un-TBAD, confirming its superiority. We also aimed to investigate the relationship between the timing of TEVAR intervention and results.

METHODS

We carried out a comprehensive literature search on multiple electronic databases including PubMed, Scopus, and EMBASE to collate and summarize all research evidence on the mid- and long-term outcomes of TEVAR in un-TBAD, as well as its relationship with intervention timing.

RESULTS

TEVAR has proven to be a safe and effective tool in un-TBAD, offering superior mid- and long-term outcomes including all-cause and aorta-related mortality, aortic-specific adverse events, aortic remodeling, and need for reintervention. Additionally, performing TEVAR during the subacute phase of dissection seems to yield optimal results.

CONCLUSION

The evidence demonstrating a survival advantage in favor TEVAR over medical therapy in un-TBAD means that with further research, particular trials and observational studies, TEVAR could become the gold-standard treatment option for un-TBAD patients.

Early experience with a novel dissection-specific stent-graft to prevent distal stent-graft-induced new entry tears after thoracic endovascular repair of chronic type B aortic dissections

PURPOSE

The aim was to report short and mid-term outcomes of a novel, investigational, dissection-specific stent-graft (DSSG), specifically designed to address the features of chronic type B aortic dissection (CTBAD) and reduce the risk of distal stent-graft-induced new entry tears (dSINE).

MATERIALS AND METHODS

A retrospective single center cohort study of all patients undergoing TEVAR with the DSSG for CTBAD from January 1, 2017 to January 31, 2020. The DSSG, which is a modified stent-graft based on the Cook Zenith Alpha Thoracic platform, has no proximal barbs and a customized longer body length with substantial taper. The second and third distal Z-stents are sited internally to avoid any contact of the metal skeleton with the dissection membrane and have reduced radial force, while the most distal stent was removed creating a distal 30 mm unsupported Dacron graft.

RESULTS

Sixteen patients (13 males, 3 females) with a median age of 66 years (range 31-79 years) underwent elective TEVAR of CTBAD using the DSSG. Six patients (38%) had an underlying connective tissue disorder. The median tapering was 10mm (range 4mm-21mm) and median length 270mm (range 210-380 mm). Technical success was achieved in all but one case (96%). One patient died within 30 days, due to retrograde type A dissection with cardiac tamponade. The 30-day rate of stroke, spinal cord ischemia and re-interventions was 0%. After median imaging follow-up time of 17 months (range 1 - 31 months), one patient developed a dSINE four months after the index procedure. After median survival follow-up of 23 months (range 2 - 35 months), one late death occurred due to traumatic brain injury, while no aortic-related death occurred during follow-up. Complete false lumen (FL) thrombosis was achieved in nine patients while the remaining six showed partial FL thrombosis. No instances of diameter increase at the level of treated aortic segment were noted with serial measurements showing either stable (n=7) or decreased (n=8) maximal transverse diameter.

CONCLUSIONS

Use of a novel DSSG with low radial force for TEVAR in the setting of CTBAD is safe and feasible. This early real-world experience shows promising mid-term effectiveness with low rates of dSINE or unplanned re-interventions and satisfactory aortic remodelling during follow-up. Longer follow-up is needed, however, before any firm conclusions can be drawn.

Influence of measurement and sizing techniques in thoracic endovascular aortic repair on outcome in acute complicated type B aortic dissections

OBJECTIVES

Thoracic endovascular aortic repair (TEVAR) is the first-line therapy in acute complicated type B aortic dissections (cTBAD). Nevertheless, no evidence-based consensus on the optimal measurement technique and sizing for TEVAR in cTBAD exists. The aim was to evaluate how different measurement and sizing techniques for TEVAR affect long-term outcomes.

METHODS

Retrospective analysis investigating the association between sizing and postoperative results after TEVAR in patients with cTBAD, treated between January 2003 and December 2020. Diameter measurements were performed perpendicular to a centreline in pre-interventional Computed tomography angiographies. Oversizing was determined by measuring aortic diameter in zone 2 of the aortic arch in relation to the implanted stent graft, and categorized into 2 sizing groups (≤10% and >10%). The primary outcome was freedom from aortic-related events. Secondary outcomes included mortality and a comparison of 3 alternative measurement techniques considering the estimated pre-dissection diameter.

RESULTS

Fifty-seven patients (median age 69, interquartile range 59.6-78.2 years) were included. Stent graft oversizing by ≤10% showed a trend towards fewer aortic-related events hazard ratio 0.455 (95% confidence interval 0.128-1.624, P = 0.225).The 3 measurement techniques using the pre-dissection aortic diameter differed by a mean of 1.7-4.0 mm with a variability of up to 8.4 mm. In none of the 57 patients, the same stent graft would have been chosen based on the different measurement techniques using an oversizing ≤10%.

CONCLUSIONS

TEVAR oversizing of ≤10% in patients with cTBAD might reduce aortic-related events up to 50%. Consensus on measurement techniques of the pre-dissection aortic diameter and stent graft sizing is of paramount importance.

Aortic Neck Dilatation Following Thoracic Endovascular Aortic Repair

OBJECTIVE

Thoracic endovascular aortic repair (TEVAR) has become a mainstay of treatment for a variety of thoracic aortic pathologies. Expansion of the proximal aortic neck after endovascular repair of abdominal aortic aneurysms has been demonstrated; however, dilatation of the proximal aortic neck after TEVAR has not been well described. We sought to describe remodeling of the proximal neck following TEVAR.

METHODS

This is a retrospective, single institution review of patients who underwent TEVAR for thoracic aortic aneurysm (TAA) and dissection with aneurysmal degeneration from 2010 to 2019. Postoperative computed tomography scans were reviewed and aortic diameter was measured in orthogonal planes using 3-dimensional centerline reconstruction software. The primary outcome was change in aortic diameter at the proximal aortic neck as compared to the initial postoperative computed tomography scan. Clinical and operative data were analyzed to identify factors associated with significant neck dilatation.

RESULTS

Of 87 patients who underwent TEVAR during the study period, 30 met inclusion criteria. Median follow up was 20.5 months. Median age was 67 years, and 15 patients (50%) were female. The proximal aortic neck experienced an overall increase over time in aortic diameter. Five mm distal to the graft showed the greatest rate of expansion, with a median increase of 1.3, 2.9, and 6.2 mm at one year, two years, and three years, respectively. When comparing patients who had mean expansion at this location of >2.0 mm/year to patients who did not, a higher percentage had dissection pathology (81.8% vs. 31.6%, P = 0.008), had graft placement at aortic landing zone 2 (36.4% vs. 5.3%, P = 0.028), and were smokers (100% vs. 52.6%, P = 0.006). Higher percent oversizing was shown to be associated with significant aortic neck dilatation for true aneurysms only.

CONCLUSIONS

Aortic neck dilatation occurs over time for the majority of patients following TEVAR with the distal neck experiencing the highest rate of expansion. Dissection pathology, aortic landing zone 2, and smoking were found to be associated with a higher rate of neck dilatation.

Analysis of clinical outcomes of one-staged hybrid procedure without thoracotomy for aorta lesion involving distal aortic arch

BACKGROUND

This study aimed to evaluate the clinical outcomes of one-staged hybrid procedure for aortic lesions involving the distal aortic arch.

METHODS

We retrospectively studied 99 consecutive patients who underwent the hybrid procedure (thoracic endovascular aortic repair combined with supra-arch branch vessel bypass) in our center between April 2009 and January 2020 for lesions involving the distal aortic arch.

RESULTS

Median age was 64.0 (57.0-69.0) years, and 83 (83.8%) patients were male. There were five deaths in the perioperative period (three due to cerebral infarction and two due to intimal rupture). During the median follow-up of 41.0 months, 20 patients died, three had endoleak, one had a newly formed intimal tear, and two had femoral artery pseudoaneurysm. The 5- and 10-year survival rates of the total population were 72.2% and 48.8%, respectively. Additionally, there was no difference in the 5-year survival rate among the four groups according to different pathologies (Type B aortic dissection, aortic ulcer, aortic aneurysm, aortic pseudoaneurysm: 74.7%, 78.2%, 61.1%, and 75.5%, respectively, p = .58). Furthermore, there was no difference in the 5- and 10-year survival rates between the two groups according to the different bypass methods (right axillary artery [RAA]-left axillary artery [LAA] vs. RAA-LAA-left common carotid artery: 74.1% vs. 68.9%, p = .38).

CONCLUSIONS

Although one-staged hybrid procedure has fewer complications in high-risk patients with lesions involving the distal aortic arch, the long-term survival rate is not optimistic.

Preliminary results of spot-stent grafting in Stanford type B aortic dissection and intramural haematoma

OBJECTIVES

METHODS

Patients undergoing thoracic endovascular aortic repair (TEVAR) for acute/subacute aortic dissection Stanford type B/intramural haematoma Stanford type B between 1997 and 2018 were identified from a prospectively maintained institutional database. In a total of 183 cases, 22 patients (7 women; median age 62 years; range 35–79 years) received SSG. The primary study end point was technical success. The primary morphological end point was false lumen thrombosis/aortic remodelling. Secondary end points were TEVAR-related mortality/morbidity and reinterventions. The median follow-up was 28.5 months (5 days–15.6 years).

RESULTS

The primary technical success rate was 100% (22/22). During follow-up, false lumen thrombosis was seen in 21 patients (95.5%) at a median of 6 days (0 days to 2.7 years) after the index procedure (limited/extended false lumen thrombosis: n = 9 vs 12). Aortic remodelling was achieved in 15 of 22 patients (68.2%) at a median of 360 days (3 days to 7.2 years). Limited/extended remodelling was observed in 8/15 and 7/15, respectively. Retrograde dissection or stent graft-induced new entry was not observed. No stroke or spinal cord injury occurred. Reinterventions were performed in 4/22 cases. The in-hospital mortality and 30-day mortality were 0%. Overall mortality during the follow-up period was 22.7% (5/22).

CONCLUSIONS

This study shows favourable technical and morphological results for SSG in selected patients with acute/subacute aortic dissection Stanford type B/intramural haematoma Stanford type B. Patient allocation to SSG remains individual. Prospective large-scale long-term data may allow refinement of the application.