Outcome comparison of thoracic endovascular aortic repair performed outside versus inside proximal landing zone length recommendation

Endovascular Repair of Penetrating Thoracic Aortic Ulcers Using Tubular Stent Grafts Versus Stent Grafts With a Proximal Scallop

PURPOSE

In penetrating aortic ulcers (PAUs), limited data support tubular thoracic endovascular aortic repair (TEVAR) as a viable treatment option. For treatment of more proximal PAUs, hybrid approaches and-more recently-scalloped TEVAR (scTEVAR) have been advocated. Outcomes of scTEVAR specifically for PAUs have not yet been reported. This study reports long-term outcomes for tubular and scTEVAR in PAUs and compares the safety profile in both cohorts regarding the significantly more proximal landing zone (LZ) for scTEVAR.

MATERIALS AND METHODS

This single-center retrospective cohort study includes all nonacute patients treated for complicated PAU with scTEVAR and tubular TEVAR. Patient and PAU characteristics as well as procedural success, complication and reintervention rates, and all-cause and aortic mortality were analyzed.

RESULTS

Of 212 TEVAR procedures reviewed, 21 patients with tubular TEVAR and 19 patients with scTEVAR were included. Patient and PAU characteristics were similar, and LZ was significantly more proximal in the scTEVAR cohort (p=0.0001), with similar number and types of supra-aortic revascularization procedures. Clinical success was reached in all 40 patients (100%), and reintervention rate was 2/21 (9.5%) and 1/19 (5.3%), respectively. Over the mean follow-up of 63 (TEVAR) and 53 (scTEVAR) months, clinical success was stable in all patients with one (abdominal) aortic-related mortality in the scTEVAR cohort.

CONCLUSION

Treatment of complicated PAUs with TEVAR as well as scTEVAR provides excellent and similar clinical success, stability of clinical success, and aortic survival with acceptable complication and reintervention rates. Scalloped TEVAR safely lengthens the proximal sealing zone to address more proximal pathologies.

CLINICAL IMPACT

Treatment of asymptomatic complicated penetrating aortic ulcers (PAUs) with thoracic endovascular aortic repair (TEVAR) provides excellent clinical success and acceptable complication and reintervention rates. More patients become amenable to endovascular treatment by including scalloped TEVAR (scTEVAR) as a means to safely lengthen the proximal sealing zone to address more proximal pathologies.

Severe Tortuosity of the Distal Descending Thoracic Aorta Affects the Accuracy of Distal Deployment During a Thoracic Endovascular Aortic Repair

PURPOSE

An accurate distal deployment is essential for successful thoracic endovascular aortic repair (TEVAR) of a paradiaphragmatic aortic aneurysm. This study aimed to investigate the anatomical and intraoperative factors that affect the accuracy of distal deployment during TEVAR.

METHODS

We conducted a retrospective review of preoperative and postoperative computed tomography scans of 426 patients undergoing TEVAR at our institution between October 2008 and May 2021, of which the stent-graft was attempted to be deployed just above the celiac axis or the superior mesenteric artery in 56 patients. Based on the anatomical factors related to the malposition (deployed >10 mm away from the target vessel) and the greater curve to the straight-line ratio (G/S ratio), the patients were categorized as severe tortuosity (n=21) and mild tortuosity (n=35) groups to compare the operative and clinical outcomes.

RESULT

Stent-graft malpositioning occurred in 21 cases. Among all anatomical variables, only the G/S ratio was significantly larger in the malpositioned cases (p=0.049). A cutoff G/S ratio value of 1.15 was determined using the receiver operating curve analysis. In the severe tortuosity group, the distal end of the stent-graft was significantly farther (median: 10.0 [interquartile range (IQR): 2.5-19.5] mm vs 3.0 [0-8.0] mm; p=0.015) from the target vessel, and the tilt angle of the stent-graft's distal edge was larger (median: 21.4 [IQR: 15.8-24.5] vs 9.5 [5.5-12.5] degree; p<0.01) than that in the mild tortuosity group. Both groups were comparable for the incidence of a primary type Ib endoleak (p=0.454), a secondary type Ib endoleak (p=1.0), and the rate of distal reintervention (p=0.276).

CONCLUSION

Severe tortuosity in the distal descending thoracic aorta is associated with a malpositioned and tilted distal end of the stent-graft.

CLINICAL IMPACT

Thoracic endovascular aortic repair (TEVAR) for paradiaphragmatic thoracic aortic aneurysms requires accurate distal landing. In this paper, a retrospective CT analysis revealed that the greater curve to the straight-line ratio (G/S ratio) was associated to affects the malposition of the stent graft, defined as being deployed more than 10 mm away from the target vessel. Further, a comparative analysis based on the G/S ratio demonstrated that severe aortic tortuosity was associated with a more distal and tilted deployment of the stent graft.

Initial Outcomes of the Gore TAG Thoracic Branch Endoprosthesis for Endovascular Repair of Blunt Thoracic Aortic Injury

BACKGROUND

Endovascular repair of blunt thoracic aortic injury (BTAI) has dramatically reduced the morbidity and mortality of intervention. Injuries requiring zone 2 coverage of the aorta traditionally require left subclavian artery (LSA) sacrifice or open revascularization. Furthermore, these injuries are associated with an increased risk of in-hospital mortality and long-term morbidity. Here we report 1-year outcomes of total endovascular repair of BTAI with the GORE® TAG® Thoracic Branch Endoprosthesis for LSA preservation.

METHODS

Across 34 investigative sites, 9 patients with BTAI requiring LSA coverage were enrolled in a nonrandomized, prospective study of a single-branched aortic endograft. The thoracic branch endoprosthesis device allows for graft placement proximal to the LSA and incorporates a single side branch for LSA perfusion.

RESULTS

This initial cohort included 8 male and 1 female patient with a median age of 43 (22, 76) and 12 months of follow-up. Five total years of follow-up are planned. All participants had grade 3 BTAI. All procedures took place between 2018 and 2019. The median injury severity score was 2 (0, 66). The median procedure time was 109 min (78, 162). All aortic injuries were repaired under general anesthesia and with heparinization. A spinal drain was used in one patient. Post-deployment balloon angioplasty was conducted in one case at the distal landing zone. There was one asymptomatic LSA branch occlusion 6 months after repair. It was attributed to the purposeful proximal deployment of the branch stent to accommodate an early vertebral takeoff. The occlusion did not require revascularization. There were no strokes, mortalities, or aortic adverse events (migration, endoleak, native aortic expansion, dissection, or thrombosis) through 12 months of follow-up.

CONCLUSIONS

Initial cohort outcomes suggest that endovascular repair of zone 2 BTAI is feasible and has favorable outcomes using the thoracic branch device with LSA preservation. Additional cases and longer-term follow-up are required for a definitive assessment of the device's safety and durability in traumatic aortic injuries.

Late Endograft Migration After Thoracic Endovascular Aortic Repair: A Systematic Review and Meta-analysis

PURPOSE

The objective of this systematic review was to report the cumulative incidence of endograft migration (EM), as well as the morbidity, reintervention rates, and mortality related to EM. This study aimed to provide evidence-based data on patient-relevant sequelae of EM after thoracic endovascular aortic repair (TEVAR) performed using contemporary aortic endografts.

MATERIALS AND METHODS

A systematic electronic search of literature in MEDLINE (via PubMed), Web of Science, and Cochrane Central Register of Controlled Trials was performed. The pooled synthesis of outcomes was performed using the inverse variance method.

RESULTS

Seven prospective non-randomized and 4 retrospective studies, including a total of 1783 patients presenting 70 EMs, were considered for the quantitative analysis. The pooled rate of EM was 4% (95% CI, 2%-7%; range, 0.2%-11%; I2=82%); pooled morbidity rate was 31% (95% CI, 12%-59%; range, 0%-100%; I2=64%) and pooled reintervention rate was 32% (95% CI, 15%-56%; range, 0%-100%; I2=55%). The pooled mortality rate due to EM was 5% (95% CI, 1%-21%; range, 0%-40%; I2=24%).

CONCLUSION

For the first time, this meta-analysis provides pooled reference estimates of EM after TEVAR. Thus, the results hold the potential to further characterize EM after TEVAR. The clinical relevance of EM is underlined by its association with high rates of endoleak-related morbidity, reintervention, and mortality. Close standardized surveillance after TEVAR for early detection of EM and prophylaxis of its sequelae is essential.

Short-term follow-up of proximal aorta remodeling after zone 2 thoracic endovascular aortic repair for acute type B aortic dissection

BACKGROUND

To evaluate the early remodeling of the proximal aorta in patients with acute type B aortic dissection (ATBAD) after zone 2 thoracic endovascular aortic repair (TEVAR).

METHODS

From January 2016 to May 2022, 53 ATBAD patients underwent zone 2 TEVAR were divided into two groups, the Castor single-branched stent-graft (CSS) group (n = 26) and the common stent-graft group (n = 27). Three-dimensional imaging created by computed tomography angiography was used to measure different parameters of the aorta, such as angulation, cross-sectional area (CSA), length and tortuosity. Early remodeling of the proximal aorta was evaluated by comparing geometric parameters of the proximal aorta before and 3 months after surgery.

RESULTS

In terms of angle, the postoperative angle of aortic arch to ascending aorta, descending aorta increased in all patients compared with that before surgery (all P < 0.05), while the angle of aortic arch to left subclavian artery increased after surgery only in the CSS group (P < 0.001); As for CSA, the CSA of distal aortic arch and true lumen increased (all P < 0.05), while the CSA of false lumen decreased in both groups after operation (all P < 0.05); Only in CSS group, the CSA of the ascending aorta, proximal aortic arch and total descending thoracic aorta decreased after surgery (all P < 0.05); In terms of length, the aortic arch prolonged after operation in both groups (P = 0.018 and P = 0.004, respectively). In addition, the ascending aorta tortuosity decreased in the CSS group after surgery (P = 0.011). There was no significant difference in the alterations of other aortic parameters after operation (P > 0.05).

CONCLUSIONS

The CSS implantation provided a more relatively safe and effective treatment for acute type B aortic dissection patients with unfavorable proximal landing zone. It can promote the earlier remodeling of the proximal aorta compared with the common stent-graft implantation after zone 2 TEVAR.

Sandwich thoracic branch endoprosthesis technique for endovascular repair of thoracic aortic aneurysm with aberrant right subclavian artery

Subclavian artery coverage is frequently required to achieve an adequate proximal seal during thoracic endovascular aortic repair. The thoracic branch endoprosthesis (TBE; W.L. Gore & Associates) is the first U.S. Food and Drug Administration-approved branched device for thoracic endovascular aortic repair, designed for left subclavian artery incorporation. However, anatomic suitability of the TBE has been shown to be limited. In the present report, we describe a novel technique using the TBE in a sandwich periscope configuration to allow for emergent repair of a ruptured thoracic aortic aneurysm with a highly angulated proximal seal zone and aberrant right subclavian artery.

Endovascular repair of thoracic aortic disease with isolated left vertebral artery and unfavorable proximal landing zone using fenestrated castor stent-graft

Objective

The main purpose of this study was to evaluate the safety and efficacy of Castor single-branched stent-graft combined with fenestrated technique in treatment of thoracic aortic disease (TAD) with unfavorable proximal landing area (PLZ) and isolated left vertebral artery (ILVA).

Methods

From January 2018 to March 2022, 8 patients with TAD (6 patients with type B aortic dissections, 1 patient with type B intramural hematomas, and 1 patient with thoracic aortic aneurysm) underwent thoracic endovascular aortic repair with fenestrated Castor stent-graft due to the existence of ILVA and unfavorable PLZ. Demographic characteristics, surgical details, postoperative complications, follow-up and postoperative CTA imaging results were collected and analyzed.

Results

The primary technical success rate was 100%. The mean operation time was 115 min (range, 70-180 min). All the left subclavian arteries (LSAs) and ILVAs of the eight patients were revascularized by fenestrated Castor stent-grafts. During the follow-up period, no deaths and complications were observed. No internal leakage, aortic rupture, retrograde type A dissection were found on computed tomography angiography. All of the LSAs and ILVAs maintained patency without stenosis.

Conclusion

Castor single-branched stent-graft implantation combined with fenestration technique may be safe and feasible for TAD patients with ILVA and unfavorable PLZ.

One year follow-up outcomes of endovascular treatment for aortic dissection with a partial micropore stent graft in which fixation of the stent is done in zone 0: A pivotal trial first in human

OBJECTIVE

This study aimed to verify the efficacy and safety of the treatment for patients diagnosed with DeBakey type I and type III thoracic aortic dissections using a partial micropore stent graft.

METHODS

We conducted a retrospective analysis of 32 patients who suffered from thoracic aortic dissection and underwent endovascular repair using a partial micropore stent graft at our center between December 2018 and January 2020.

RESULTS

The technical success rate for 32 patients was 100 %, while no 30-day mortality was observed. In the 30 patients finished follow-ups, 30 (mean: 1 per patient) micropore stents were implanted, while the openings of 90 (mean: 3 per patient) aortic arch branches were covered by the stents. After more than 12 months follow-up, 26 (86.7 %) of the 30 patients presented with a complete thrombosis in the false lumen, and 4 (13.3 %) patients presented with a partial thrombosis in the false lumen. All 90 aortic arch branches were patent. No aortic arch branch artery stenosis or occlusion was observed.

CONCLUSIONS

The outcomes obtained during 12 months of follow-up suggested that performing endovascular repair for thoracic aortic dissection patients with a partial micropore stent graft is safe and effective, maintaining the patency of aortic arch branch vessels.

Outcomes of thoracic endovascular aortic repair with fenestrated surgeon-modified stent-graft for type B aortic dissections involving the aortic arch

Objectives

This retrospective analysis aimed to evaluate the early and midterm outcomes of thoracic endovascular aortic repair (TEVAR) with fenestrated surgeon-modified stent-graft (f-SMSG) for type B aortic dissections (TBAD) involving the aortic arch.

Methods

From March 2016 to April 2021, 47 consecutive patients were treated using TEVAR with f-SMSG. All patients were diagnosed with TBAD involving the aortic arch.

Results

In total, 47 patients with TBAD involving the aortic arch were treated with f-SMSGs. There were 21 zone 1 and 26 zone 2 TEVAR, and 65 arteries were revascularized successfully with fenestrations. Technical success was achieved in 46 patients (97.88%). The 30-day estimated survival (± SE) and reintervention was 93.6 ± 1.0% (95% Confidence Interval [CI], 92.6-94.6%) and 91.5 ± 1.2% (95% CI, 90.3-92.7%), respectively. During a median follow-up of 51 months (range, 16-71 months), 1 patient died of rupture of aortic dissection (AD) and 3 patients died of non-aortic-related reasons. Reintervention was performed for four patients, including two patients of type IA entry flow and two patients of type IB entry flow. No occlusion of the supra-aortic trunk was observed. The estimated survival and reintervention (± SE) at 4 years was 88.7 ± 1.4% (95% CI, 87.3-90.1%) and 84.8 ± 1.5% (95% CI, 83.3-86.3%), respectively.

Conclusion

Thoracic endovascular aortic repair with f-SMSG is an alternative treatment option for TBAD involving the aortic arch in high-volume centers.

Dynamic Morphology of the Ascending Aorta and Its Implications for Proximal Landing in Thoracic Endovascular Aortic Repair

In this study, we assessed the dynamic segmental anatomy of the entire ascending aorta (AA), enabling the determination of a favorable proximal landing zone and appropriate aortic sizing for the most proximal thoracic endovascular aortic repair (TEVAR). Methods: Patients with a non-operated AA (diameter < 40 mm) underwent electrocardiogram-gated computed tomography angiography (ECG-CTA) of the entire AA in the systolic and diastolic phases. For each plane of each segment, the maximum and minimum diameters in the systole and diastole phases were recorded. The Wilcoxon signed-rank test was used to compare aortic size values. Results: A total of 100 patients were enrolled (53% male; median age 82.1 years; age range 76.8−85.1). Analysis of the dynamic plane dimensions of the AA during the cardiac cycle showed significantly higher systolic values than diastolic values (p < 0.001). Analysis of the proximal AA segment showed greater distal plane values than proximal plane values (p < 0.001), showing a reversed funnel form. At the mid-ascending segment, the dynamic values did not notably differ between the distal plane and the proximal segmental plane, demonstrating a cylindrical form. At the distal segment of the AA, the proximal plane values were larger than the distal segmental plane values (p < 0.001), thus generating a funnel form. Conclusions: The entire AA showed greater systolic than diastolic aortic dimensions throughout the cardiac cycle. The mid-ascending and distal-ascending segments showed favorable forms for TEVAR using a regular cylindrical endograft design. The most proximal segment of the AA showed a pronounced conical form; therefore, a specific endograft design should be considered.

Comparison of techniques for left subclavian artery preservation during thoracic endovascular aortic repair: A systematic review and single-arm meta-analysis of both endovascular and surgical revascularization

Background

Currently, the optimal technique to revascularize the left subclavian artery (LSA) during thoracic endovascular aortic repair (TEVAR) remains controversial. Our study seeks to characterize early and late clinical results and to assess the advantages and disadvantages of endovascular vs. surgical strategies for the preservation of LSA.

Methods

PubMed, Embase and Cochrane Library searches were conducted under the PRISMA (Preferred Reporting Items for Systematic review and Meta-Analyses) standards. Only literature published after January 1994 was included. Studies reporting on endovascular revascularization (ER), surgical revascularization (SR) for LSA preservation were included. 30-day mortality and morbidity rates, restenosis rates, and rates of early and late reintervention are measured as outcomes.

Results

A total of 28 studies involving 2,759 patients were reviewed. All articles were retrospective in design. Single-arm analysis found no significant statistical differences in ER vs. SR in terms of 30-day mortality and perioperative complication rates. The mean follow-up time for the ER cohort was 12.9 months and for the SR cohort was 26.6 months, respectively. Subgroup analysis revealed a higher risk of perioperative stroke (4.2%) and endoleaks (14.2%) with the chimney technique compared to the fenestrated and single-branched stent approaches. Analysis of the double-arm studies did not yield statistically significant results.

Conclusion

Both ER and SR are safe and feasible in the preservation of LSA while achieving an adequate proximal landing zone. Among ER strategies, the chimney technique may presents a greater risk of neurological complications and endoleaks, while the single-branched stent grafts demonstrate the lowest complication rate, and the fenestration method for revascularization lies in an intermediate position. Given that the data quality of the included studies were relatively not satisfactory, more randomized controlled trials (RCTs) are needed to provide convincing evidence for optimal approaches to LSA revascularization in the future.

Homemade fenestrated physician-modified stent-grafts for arch aortic degenerative aneurysms

OBJECTIVE

To evaluate early and medium-term outcomes of single and double fenestrated physician-modified endovascular grafts (PMEGs) for total endovascular degenerative aortic arch aneurysm repair.

METHODS

This single-center retrospective analysis of prospectively collected data included 52 patients, from August 2013 through January 2021, undergoing home-made fenestrated thoracic endovascular aortic repair (TEVAR) for degenerative aortic aneurysms. In all cases a distal smaller fenestration for the left subclavian artery (LSA) was fashioned and the only one stented. For double-fenestrated endograft a proximal larger fenestration that incorporated both the brachiocephalic trunk and left common carotid artery was added.

RESULTS

52 patients with degenerative aortic arch aneurysms were treated. There were 36 men and the mean age was 75 ± 8 years. 31% treated with a single LSA fenestration, while 69% had a double-fenestrated TEVAR. 10% (n=5) were emergent procedures. Technical success was 100%. The median time requirement for stent graft modification was 22 ± 6 minutes. Thirty-day mortality was 2% (n=1). 5 patients (10%) had a cerebrovascular event including 2 transient ischemic attack, one minor stroke with full neurological recovery and 2 with sequelae. 2 patients (4%) experienced perioperative retrograde dissection during follow-up. No patient had a type I, type III or type II endoleak from the LSA. No patient required re-intervention. All supra-aortic trunks were patent. During a mean follow up of 18 ± 11 months, there were no conversion to open surgical repair, aortic rupture or paraplegia.

CONCLUSIONS

Single or double PMEG is a safe and suitable tool for the treatment of high morbidity pathology such as aortic arch degenerative aneurysm repair. This device can be used in elective and emergency patients.

Hybrid type II and frozen elephant trunk in acute Stanford type A aortic dissections

Objectives. Composite frozen elephant trunk is an increasingly popular solution for complex aortic pathologies. This review aims to compare outcomes of zone 0 type II hybrid (hybrid II) with the composite frozen elephant trunk (FET) technique in managing acute Stanford type A aortic dissections. Methods. PubMed and Embase were systematically searched using PRISMA protocol. 11 relevant studies describing the outcomes of hybrid II arch repair and FET techniques in patients with type A aortic dissection were included in the meta-analysis. The study focused on early post-operative 30-day outcomes analysing mortality, stroke, spinal cord injury, renal impairment requiring dialysis, bleeding and lung infection. Results. 1305 patients were included in the analysis - 343 receiving hybrid II repair and 962 treated with the FET. Meta-analysis of proportions showed Hybrid II was associated with less early mortality [5.0 (CI 3.1-7.8) vs 8.1 (CI 6.5-10.0) %], stroke [2.3 (CI 1.1-4.6) vs 7.0 (CI 5.5-8.8) %], spinal cord injury [2.0 (CI 0.9-4.3) vs 3.8 (CI 2.8-5.3) %], renal impairment requiring dialysis [7.9 (CI 5.5-11.2) vs 11.8 (CI 9.8-14.0) %], reoperation for bleeding [3.9 (CI 1.8-8.4) vs 10.6 (CI 8.1-13.8) %] and lung infection [14.8 (CI 10.8-20.0) vs 20.7 (CI 16.9-25.1) %]. Conclusion. Hybrid II should be considered in favour of FET technique in acute Stanford type A dissection patients who are at higher risk due to age and comorbidities.

Right-Sided Chylothorax: A Case Report of an Uncommon Manifestation After Cervical Debranching Thoracic Endovascular Aneurysm Repair

A 70-year-old man was admitted to our hospital with a thoracic aortic aneurysm. He underwent elective thoracic endovascular aneurysm repair with left common carotid artery-left subclavian artery bypass via the left supraclavicular approach. During the bypass, the thoracic duct was injured and ligated. On postoperative day 3, the patient complained of dyspnea. Chest radiography revealed a massive right-sided pleural effusion. On postoperative day 5, he was diagnosed with right-sided chylothorax and underwent chest tube insertion. The next day, a left-sided chylothorax was noted, and chest tube drainage was performed. Conservative management, including nil per os and subcutaneous octreotide (300 μg/day) injection, was carried out for 2 weeks; subsequently, the chylothorax improved. This report highlights the diagnostic challenge of right-sided chylothorax after debranching thoracic endovascular aneurysm repair.

Anatomical analysis of the aortic arch and feasibility study of double and triple branched thoracic endografts in the treatment of isolated arch pathologies

OBJECTIVES

The aim of this study was to determine the proportion of patients undergoing open arch repair who would be anatomically suitable for multi-branched endovascular arch repair.

METHODS

This study was a single-centre review of patients undergoing open arch repair between 2000 and 2020. Anatomical feasibility was determined by comparing arch measurements to the anatomical criteria of the Zenith® double and triple inner branched-arch endografts (Cook Medical) and the Relay® double arch branched device (Terumo-Aortic).

RESULTS

Ninety (90) patients were included in this study, with 43/90 presenting degenerative aneurysm. The distance between the sinotubular junction and the brachiocephalic trunk measured 114 ± 30 mm on the outer curvature, and the maximum diameter of the proximal landing zone (PLZ) was 41 ± 11mm. A total of 42/90 patients (47%) were anatomically suitable for at least 1 stent graft and 29/90 patients (32%) were eligible for a triple-branched endograft. The most important determinant factors of anatomical suitability were the PLZ diameter (Cramer's V = 0.743, P < 0.001) and length (Cramer's V = 0.777, P < 0.001).

CONCLUSIONS

This study shows that the proportion of patients who may be anatomically suitable for branched-arch repair remains limited. The PLZ dimensions tend to be the most important anatomical limitations and should receive more emphasis in the development of branched-arch devices.

Aortic Healing Appears to Occur Rapidly after Successful Endovascular Sealing of Blunt Thoracic Aortic Injury

OBJECTIVES

The traumatic nature of blunt thoracic aortic injury (BTAI) would suggest that healing of the aorta would occur once the injured area is shielded from aortic pressure. This would be in contrast to degenerative aortic diseases which often continue to degenerate despite coverage. We hypothesize that after successful thoracic aortic endografting (TEVAR) that the aorta rapidly heals itself leaving minimal to no trace of the residual injury.

METHODS

BTAI that were successfully covered with TEVAR from 2006-2019 were collected. Those with failed sealing or lack of follow up scans were excluded. Centerline aortic diameters were measured at healthy aorta 1 cm above (D1) and below the injury (D3) and at the widest point of injury (D2) on pre- and initial post-operative computed tomography (CT) scans. Post-operative CTs were examined for residual signs of aortic injury including residual peri-aortic hematoma, persistent thrombosed pseudoaneurysm, or thickened aortic wall. Diameter changes in the healthy and injured aortic segments were compared pre and post TEVAR. Aortic diameter changes were analyzed with Students t-test.

RESULTS

Twenty-four patients were identified with sealed BTAI. Mean graft diameter was 24.2 ± 3.2 mm with oversizing of 10.74 ± 6.1 % at D1 and 19.52 ± 10.22 % at D3. Postoperative CTs occurred at 61.25 ± 123.6 days with one outlier at 602 days. Injured aortic segments (D2) had significantly larger diameters compared to D1 (28.94 ± 5.08mm vs. 22.14 ± 3.08 mm, P<0.001).). After TEVAR, 23/24 (95.8%) had no residual radiographic evidence of aortic injury by 2 months. One patient had a persistent thrombosed pseudoaneurysm likely due to a more than 50% disruption of the aortic wall. Post TEVAR, there was a significant diameter reduction at D2 by 13.8% (29.10 ± 5.27mm vs. 24.8 ± 4.2 mm, p <0.001) which was within 2.45% of the mean stent graft diameter. Healthy aorta dilated to accommodate the graft by 9% at D1 (21.9 ± 3.0 vs. 23.7 ± 2.5 mm, p < 0.001) and 17% at D3 (20.6 ± 3.4 mm vs. 23.6 ± 3.2 mm, p < 0.001).

CONCLUSIONS

TEVAR promotes rapid aortic healing in BTAI with no evidence of residual aortic injury suggesting that a long term seal is not necessary. The healthy aorta dilates to the stent graft size, as expected, while the injured aortic segment heals around the stent graft and assumes its diameter as well. Massive disruption of the aortic wall may preclude early healing.

Determination of Optimal and Safest Proximal Sealing Length During Thoracic Endovascular Aortic Repair

OBJECTIVE

To determine the optimal and safest proximal sealing length (PSL) during thoracic endovascular aortic repair (TEVAR), depending on anatomical aortic arch types and proximal landing zones (LZs).

METHODS

This was a single centre retrospective observational study of consecutive TEVAR patients (2008-2020). All aortic pathologies requiring Ishimaru landing zone (LZ) 0 - 3 were included; results were stratified by aortic arch type. The PSL was measured as the length of complete aortic wall to endograft apposition at the level of the proximal neck. The primary endpoint was proximal failure (type 1A endoleak, endograft migration, or re-intervention requiring proximal graft extension). Freedom from proximal failure was estimated with Kaplan-Meier curves. An "optimal" sealing length (PSL cutoff maximising sensitivity + specificity for proximal failure) and "safest length" (PSL cutoff determining ≥ 90% sensitivity) were identified using receiver operating characteristic curve analysis.

RESULTS

One hundred and forty patients received TEVAR; mean ± standard deviation PSL was 29 ± 9 mm. Freedom from proximal endograft failure at five years (median 31 months) was 82.4% (95% confidence interval [CI] 72 - 95); the shorter the PSL, the greater was the risk of failure (hazard ratio 0.90, 95% CI 0.84 - 0.97; p = .004). Overall optimal and safest PSL were 25 mm (sensitivity 78%, specificity 66%) and 30 mm (sensitivity 92%, specificity 30%), respectively. In type I arch, the optimal PSL was 22 mm (sensitivity 50%, specificity 87%). In type II, the optimal PSL was 25 mm (sensitivity 89%, specificity 59%) overall and 27 mm for type II/LZ 2 - 3 (sensitivity 31%, specificity 68%). For type III, the optimal PSL was 27 mm (sensitivity 80%, specificity 87%); the safest was 30 mm (sensitivity 100%, specificity 61%) In type III/LZ 2 - 3, the optimal PSL was 27 mm (sensitivity 31%, specificity 68%) and safest was 30 mm (sensitivity 100%, specificity 55%).

CONCLUSION

A 20 mm PSL may be acceptable only for type I arches. For types II/III, that represent the majority of cases, a 25 - 30 mm PSL may be required for a safe and durable TEVAR.