A more proximal landing zone is preferred for thoracic endovascular repair of acute type B aortic dissections

Hemodynamic analysis of thoracic endovascular aortic repair with left subclavian artery reconstructed by chimney stent

ObjectivesThe purpose of this study was to investigate the hemodynamic consequences of thoracic endovascular aortic repair which reconstructed left subclavian artery by chimney stent (ch-TEVAR).MethodsTwo patients who underwent thoracic endovascular aortic repair (TEVAR) and left subclavian artery (LSA) reconstruction using chimney stents were selected. Preoperative and postoperative CTA images were collected to reconstruct hemodynamic models for comparing and analyzing blood pressure, blood flow velocity, and wall shear stress in the aortic arch and its major branches. Concurrently, morphological alterations and position of chimney stent were also assessed.ResultsAfter the reconstruction of LSA in ch-TEVAR, no endoleak was seen, but the stent in LSA was compressed. The blood flow velocity of the LSA increased and disordered, the pressure was reduced, and the WSS was increased. Even more, there were a large amount of turbulence found in the LSA of one case, and its LSA was blocked.ConclusionChimney stent reduces the occurrence of endoleak due to its excellent deformation ability, but the compressed stent has a greater impact on the hemodynamics of LSA and eventually leads to LSA occlusion; in order to keep the LSA unobstructed, it is necessary to pay attention to the position of the chimney stent and keep it straight and do not fold or twist. Chimney stent has little influence on the aortic arch and the rest of the aortic arch branches.

Proximal Aortic Landing Zone Dilation Following Thoracic Endovascular Aortic Repair for Type B Aortic Dissection: Incidence and Clinical Implications

BACKGROUND

This study aimed to assess the incidence, predictors, and clinical relevance of proximal aortic landing zone dilation (PALD) following thoracic endovascular aortic repair (TEVAR) for acute and chronic type B aortic dissection (TBAD).

METHODS

A retrospective analysis of 47 patients who underwent TEVAR for TBAD at a single center was conducted. PALD was defined as a ≥5 mm increase in aortic diameter at 2 of 3 measurement sites (at 0, 1, and 2 cm distal to the stent graft proximal edge) at postoperative computed tomography angiography. The primary endpoint was the development of PALD. Secondary endpoints included entry fIow type IA, device migration and reintervention rates. Kaplan-Meier analyses was used to evaluate PALD-free survival.

RESULTS

PALD occurred in 19% of patients (n = 9) during a median follow-up of 62 months. A stent graft diameter >36 mm significantly predicted PALD (P = 0.022), with an area under the curve of 0.75 (sensitivity: 89%, specificity: 58%). No significant associations were found between PALD and reinterventions or type Ia entry flow. Kaplan-Meier analysis revealed a median PALD-free survival of 156 months (95% confidence interval: 92-210). Patients with PALD demonstrated a greater increase in aortic diameter at maximum follow-up compared to non-PALD patients (P < 0.001). Other demographic, anatomic, and procedural factors were not associated with PALD, and especially oversizing did not correlate with PALD development.

CONCLUSION

PALD occurred in a significant proportion of patients following TEVAR for TBAD, with stent graft diameter serving as key predictor. PALD did not correlate with adverse clinical outcomes in this cohort.

Mid-term outcomes of the fenestration, branched stent-graft, and hybrid techniques in the treatment of thoracic aortic pathologies involving the left subclavian artery

OBJECTIVE

To compare the midterm outcomes of fenestration, branched stent-graft thoracic endovascular aortic repair, and hybrid procedures in treating aortic arch pathologies involving the left subclavian artery.

METHODS

We collected the clinical data from 144 patients with aortic arch pathologies involving and only involving the left subclavian artery (LSA) who underwent fenestration, branched stent-graft thoracic endovascular aortic repair, and hybrid procedures from November 2015 and December 2022 at a single center. Among the patients, 68 were treated by fenestration, 61 by branched stent-grafts, and 15 by hybrid surgery. The clinical data was retrospectively analyzed and compared. The primary outcome indicators included technical success and in-hospital mortality; others included the incidence of endoleaks, spinal cord ischemia, LSA patency, stent-related entry tear, aortic-related reintervention, operative time, blood loss, and aortic remodeling.

RESULTS

The technical success rate was 83.8%, 95.1%, and 100% (p = .046), and the in-hospital mortality rate was 1.5% (n = 1), 0%, and 0% (p = 1.000) in the fenestration, branched stent-graft, and hybrid surgery groups. Type I or III endoleaks occurred in 16.2% (n = 11), 4.9% (n = 3), and 0% of patients, respectively (p = .046). The operative time, blood loss, and hospitalization duration of the hybrid surgery group was significantly higher than those of the other two groups (p < .05). However, the surgery-related costs and total costs in the hybrid surgery group were lower than the other two groups (p < .001). The rate of LSA patency was 100% in the fenestration group and 98.3% in the branched stent-graft group (p = .475). The all-cause mortality rates were 10.9% (n = 7), 6.9% (n = 4), and 0%, respectively (p = .359). Spinal cord ischemia and other complications were not significantly different in each group, both in the perioperative and postoperative periods. In the subgroup analysis of patients with AD, the incidence of endoleaks was 28.9% (n = 13), 7.0% (n = 3), and 0%, respectively (p = .011), and stent-related new entry tears in each group were 2.2% (n = 1), 18.6% (n = 8), and 14.3% (n = 1), respectively, p = .032. The overall cumulative survival rate at 2 years was 90.0%, 92.4%, and 100%, respectively (p = .508). The true lumen area of the aortic arch and descending thoracic aorta in the stent segment was significantly larger postoperatively compared to that preoperatively in both of these three groups.

CONCLUSION

The fenestration technique is sophisticated with long learning curve and is prone to complications such as endoleaks with inexperience. Branched grafts are at greater risk of stent-related entry tears, which result in a higher rate of re-intervention. The hybrid technique broadens the indications for patients with aortic arch vessel variation and generally costs less, but the operative time is longer. Surgeons should select the optimal solution based on each patient's condition to achieve satisfactory results.

Influence of Left Subclavian Artery Stent Graft Geometry on Blood Hemodynamics in Thoracic Endovascular Aortic Repair

The objective of this research is to analyze the hemodynamic differences in five configurations of left subclavian artery (LSA) stent grafts after LSA endovascular reconstruction in thoracic endovascular aortic repair (TEVAR). For numerical simulation, one three-dimensional thoracic aortic geometry model with an LSA stent graft retrograde curved orientation was reconstructed from post-TEVAR computed tomography angiography (CTA) images, and four potential LSA graft configurations were modified and reconstructed: three straight (0, 2, and 10 mm aortic extension) and one anterograde configuration. The blood perfusion of the LSA, flow field, and hemodynamic wall parameters were analyzed. The vortex evolution process was visualized by the Liutex method which enables accurate extraction of the pure rigid rotational motion of fluid and is highly suitable for identifying the vortex structure of blood flow near the vessel wall. The average flow in the retrograde configuration decreased by 11.2% compared to that in the basic configuration. When the LSA stent graft extends in the aortic lumen, flow separation is observed, and vortex structures begin to form at the proximal inferior arterial geometry and the wall of the extension in late systole. A greater extension length and inflow angle upstream resulted in a greater oscillatory shear index (OSI) and relative residence time (RRT) on the nearby wall of the posterior flow field of the extension. Shorter intra-aortic extension length (<10 mm) and smaller LSA stent graft inflow angle (<120 deg) may be recommended in TEVAR, considering LSA perfusion and minimized flow field disturbance.

Management and follow-up of patient with circumferential type B aortic dissection using GORE thoracic-branch endograft

Type B aortic dissection with high-risk features such as a large entry tear, false lumen, and circumferential dissection has a greater chance of progression and rupture without definitive surgical intervention. Traditional thoracic endovascular aortic repair of dissection with proximal zone 1 landing requires extensive aortic arch debranching to minimize the risk of ischemic stroke with endograft deployment. Recent developments in endovascular grafts for thoracic endovascular aortic repair have allowed for an optimized approach in challenging cases. We present the case of a 53-year-old male with circumferential type B aortic dissection and higher-risk features treated with a staged right-to-left carotid bypass and subsequent thoracic endovascular aortic repair with a GOREⓇ TAGⓇ Thoracic Branch Endoprosthesis for zone 1 proximal landing.

Thoracic endovascular aortic repair with unibody single-branched stent-graft for type B aortic dissection: a real-world multicenter study

OBJECTIVE

To evaluate the outcome of TEVAR for TBAD and revascularization of LSA with Castor single-branched stent-graft.

SUMMARY BACKGROUND DATA

One-stage thoracic endovascular aortic repair (TEVAR) and revascularization of left subclavian artery (LSA) of type B aortic dissection (TBAD) with off-the-shelf stent-graft is limited.

METHODS

A multicenter study consisting of consecutive patients from four different centers in China treated with Castor single-branched stent-graft for TBAD was conducted. Rate of technical success, mortality, complications, and reinterventions were evaluated.

RESULTS

Between September 2018 and April 2022, 180 consecutive patients with TBAD received TEVAR with Castor single-branched stent-graft. Technical success was achieved in all patients. The mean oversize ratio at the proximal landing zone was 4.9±3.8% (median, 3.7; IQR, 2.0-6.9%). Five patients died within the first 30 days after the operation or during hospitalization. Early reintervention was performed in one case. The median follow-up was 18.0 months (IQR, 13-24 months). Five patients died during follow-up, including three cases of respiratory failure, one case of immune thrombocytopenia purpura, and one case of a cerebral hemorrhage. Three patients had reintervention. In total, three cases of stroke were recorded, which were all within 30 days after the operation. Image data at 1 year presented complete thrombosis in 97.1% cases for the false lumen covered by the stent-graft.

CONCLUSIONS

TEVAR with Castor device for treatment of TBAD and revascularization of LSA is a feasible and safe technique. The deployment procedure is safe, easy, and accurate. Castor devices meets the hemodynamical and biomechanical requirement of elastic aorta and could restore the physiological blood flow pattern of LSA.

Comparison of clinical outcomes between Castor single-branched stent graft and in situ fenestration in treating Stanford type B aortic dissection involving the left subclavian artery: A retrospective case-control study

Stanford type B aortic dissection involving the left subclavian artery (LSA) poses significant clinical challenges. The Castor single-branch stent graft and in situ fenestration are commonly used techniques, but the better endovascular treatment remains debated. This study evaluates the clinical effects of the Castor single-branched stent graft versus in situ fenestration in treating Stanford type B aortic dissection involving the LSA. We selected 75 patients with Stanford type B aortic dissection involving the LSA, admitted to the Second Affiliated Hospital of Nanchang University from January 2018 to May 2022. All patients underwent thoracic endovascular aortic repair; 34 received the Castor single-branched stent graft, while 41 underwent in situ fenestration. Clinical efficacy and perioperative complications were compared. The technical success rate of the Castor single-branch stent graft was significantly higher than that of in situ fenestration (97.06% vs 80.49%, P = .04). The Castor group exhibited significantly better outcomes in operative time (136.45 ± 25.53 min vs 157.08 ± 18.14 min), LSA blood flow recovery time (6.8 ± 2.3 min vs 20.1 ± 9.8 min), blood loss (29.03 ± 9.78 mL vs 35.69 ± 10.77 mL), contrast medium usage (288.71 ± 72.70 mL vs 352.78 ± 81.02 mL), and immediate postoperative endoleaks (1/34 vs 7/41) (P < .05). Stroke incidence (1/34 vs 2/41) and perioperative mortality (0/34 vs 1/41) were similar (P > .05). Hospital stays were comparable (15.71 ± 6.04 days vs 14.22 ± 5.01 days, P = .28). However, the cost of medical supplies (154,168.62 ± 28,288.44 CNY vs 119,589.72 ± 34,199.67 CNY) and total hospital expenses (192,665.88 ± 40,027.99 CNY vs 153,920.47 ± 42,670.87 CNY) were significantly higher in the Castor group (P < .05). The median follow-up time was 9 months (1-60 months). Follow-up showed similar 30-day postoperative mortality (1/41 vs 0/34, P = 1.00), stent patency (33/34 vs 39/41, P = .67), and stent migration rates (0/34 vs 1/41, P = 1.00). However, the endoleak rate was significantly higher in the in situ fenestration group (11/41 vs 1/34, P = .01). Both the Castor single-branch stent graft and the in situ fenestration technique effectively protect and reconstruct the LSA in Stanford type B aortic dissection, with the Castor single-branch stent graft showing higher technical success and fewer complications, indicating better clinical potential.

Aortic arch anatomical differences in male type B aortic dissection patients vs. healthy male individuals

BACKGROUND

Understanding the distinct anatomical differences between patients with type B aortic dissection (TBAD) and control patients (CPs) can enhance our knowledge of normal and pathological aortic dimensions. This study aimed to deepen our knowledge of these dimensions by measuring and comparing the anatomical indices of the aortic arch in male patients with TBAD and non-TBAD male patients.

METHODS

In this cross-sectional observational study, 62 TBAD patients (TBADPs) and 43 CPs were assessed. Using a fit centerline approach, we identified three pivotal anatomical landmarks: Point A, Point B, and Point C. These landmarks represented intersections of the aortic arch with the brachiocephalic trunk, left common carotid artery, and left subclavian artery, respectively. These points defined Zones 1, 2, and 3, which collectively span the entire proximal aorta from the proximal end of the aortic valve to Point C. Our analyses compared key anatomical indices such as diameter of the circumscribed circle (Dcirc), ellipticity, curvature, tortuosity between TBADP and CP at critical points and regions.

RESULTS

TBADPs showed a more circular cross-sectional shape at Points A, B and C, as indicated by reduced values of Dcirc_A (P = 0.031), ellipticity_A (P = 0.034) and ellipticity_B (P = 0.048), together with a significant decrease in Dcirc_C (P = 0.015) and ellipticity_C (P = 0.007). The aortic arch in TBADPs showed enhanced tortuosity in Zone 1 (p = 0.002) and extended elongation in Zone 3 (p = 0.001).

CONCLUSIONS

The study found that the aortic arch in male TBAD patients is more circular near its primary branches, has greater tortuosity in Zone 1, and is longer in Zone 3 compared to male control patients.

Predicting the need for subclavian artery revascularization in thoracic endovascular aortic repair: A systematic review and meta-analysis

OBJECTIVE

This systematic review and meta-analysis aims to investigate the effectiveness of left subclavian artery revascularization compared with non-revascularization in thoracic endovascular aortic repair, and to summarize the current evidence on its indications.

METHODS

A computerized search was conducted across multiple databases, including MEDLINE, SCOPUS, Cochrane Library, and Web of Science, for studies published up to November 2023. Study selection, data abstraction, and quality assessment (using the Newcastle-Ottawa Scale) were independently conducted by two reviewers, with a third author resolving discrepancies. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using random-effects models and publication bias was assessed using funnel plots.

RESULTS

In the 76 included studies, left subclavian artery revascularization was associated with reduced risks of stroke (OR, 0.67; 95% CI, 0.45-0.98; n = 15,331), spinal cord ischemia (OR, 0.75; 95% CI, 0.56-0.99; n = 11,995), and arm ischemia (OR, 0.09; 95% CI, 0.01-0.59; n = 8438). No significant reduction in paraplegia (OR, 0.56; 95% CI, 0.21-1.47; n = 1802) or mortality (OR, 0.77; 95% CI, 0.53-1.12; n = 11,831) was observed. Moreover, the risk of endoleak was comparable in both groups (OR, 1.25; 95% CI, 0.55-2.84; P = .60; n = 793), whereas the risk of reintervention was significantly higher in the revascularization group (OR, 1.98; 95% CI, 1.03-3.83; P = .04; n = 272). Both groups had similar risks of major (OR, 0.45; 95% CI, 0.19-1.09; P = .08; n = 1113), minor (OR, 0.21; 95% CI, 0.01-3.45; P = .27; n = 183), renal (OR, 0.61; 95% CI, 0.12-3.06; P = .55; n = 310), and pulmonary (OR, 0.59; 95% CI, 0.16-2.15; P = .42; n = 8083) complications. The most frequent indications for left subclavian artery revascularization were primary prevention of spinal cord ischemia, augmentation of the landing zone, and primary stroke prevention.

CONCLUSIONS

Left subclavian artery revascularization in thoracic endovascular aortic repair was associated with reduced neurological complications but was not found to impact mortality. The study highlights important indications for revascularization as well as significant predictors of complications, providing a basis for clinical decision-making and future research.

Hemodynamic changes for half cover left subclavian artery ostium during thoracic endovascular aortic repair

Purpose

Some clinicians use endografts to cover half the left subclavian artery (LSA) ostium to cure some cases with insufficient proximal landing zone (PLZ) in thoracic endovascular aortic repair (TEVAR) treatment. We used computational fluid dynamics (CFD) to study the hemodynamic changes in the LSA because they may cause acute thrombosis or arteriosclerosis.

Methods

The digital model of the aortic arch was established and named model A, which only included the supraarch branch of the LSA. By directly covering half of the LSA ostium, which was named as model B. All established models were imported into the Gambit grid division software for grid division and were subsequently imported into the Fluent software for hemodynamic numerical simulation and calculation to analyze the related changes in LSA hemodynamic parameters after stent implantation.

Results

Under the same aortic inlet flow, in model B, the local blood flow velocity of the LSA ostium increased and the whole blood flow velocity at the distal end decreased. The average wall shear stress (WSS) of the LSA was significantly decreased. Meanwhile there was an obvious turbulent flow in the LSA lumen, and the related blood flow state was disordered.

Conclusion

CFD research confirmed that the implantation of an endograft covering half the LSA ostium can cause obvious hemodynamic changes, which is likely to cause a long-term arteriosclerosis or acute thrombosis of the LSA, finally increasing the risk of stroke. Once this operation is performed in some specific clinical cases for simplicity and economy, it seems that we should actively antiplatelet and follow up regularly.

Treatment for Stanford type B aortic dissection with insufficient anchoring region using castor integrated branched aortic stent graft

Background

To investigate the clinical efficacy of Castor integrated branched aortic stent graft for the treatment of Stanford type B aortic dissection with insufficient anchoring area.

Methods

Retrospective analysis of clinical data of 26 patients with Stanford type B aortic dissection with insufficient anchoring region (<15 mm) treated by Castor branched aortic stent graft from September 2018 to June 2022 at Ganzhou People's Hospital, including 23 acute cases and 3 chronic cases.

Results

Surgical procedures were successfully performed in all 26 patients, and during the perioperative period no complications occurred, such as cerebrovascular accident, stenosis or occlusion of left subclavian artery, progression of reverse avulsion of aortic dissection, and paraplegia. During the operation 2 patients had a small amount of type I endoleak, which disappeared during the postoperative follow-up. The other patients had good postoperative follow-up results. Review of the aortic CTA indicated good stent morphology with patency of the left subclavian artery.

Conclusions

The Castor integrated branched aortic stent graft expanded the indications for endoluminal treatment for Stanford type B aortic dissection, which can avoid open surgery and has good clinical outcomes.

Clinical comparative analysis of 3D printing-assisted extracorporeal pre-fenestration and Castor integrated branch stent techniques in treating type B aortic dissections with inadequate proximal landing zones

BACKGROUND

This study aims to compare the clinical effects of two distinct surgical approaches, namely 3D printing-assisted extracorporeal pre-fenestration and Castor integrated branch stent techniques, in treating patients with Stanford type B aortic dissections (TBAD) characterized by inadequate proximal landing zones.

METHODS

A retrospective analysis was conducted on 84 patients with type B aortic dissection (TBAD) who underwent thoracic endovascular aortic repair (TEVAR) with left subclavian artery (LSA) reconstruction at our center from January 2022 to July 2023. Based on the different surgical approaches, the patients were divided into two groups: the group assisted by 3D printing for extracorporeal pre-fenestration (n = 44) and the group using the castor integrated branch stent (n = 40). Clinical indicators: including general patient information, operative time, surgical success rate, intraoperative and postoperative complication rates, re-intervention rate, and mortality, as well as postoperative aortic remodeling, were compared between the two groups. The endpoint of this study is the post-TEVAR mortality rate in patients.

RESULTS

The surgical success rate and device deployment success rate were 100% in both groups, with no statistically significant difference (P > 0.05). However, the group assisted by 3D printing for extracorporeal pre-fenestration had a significantly longer operative time (184.20 ± 54.857 min) compared to the group using the castor integrated branch stent (152.75 ± 33.068 min), with a statistically significant difference (t = 3.215, p = 0.002, P < 0.05). Moreover, the incidence of postoperative cerebral infarction and beak sign was significantly lower in the group assisted by 3D printing for extracorporeal pre-fenestration compared to the castor-integrated branch stent group, demonstrating statistical significance. There were no significant differences between the two groups in terms of other postoperative complication rates and aortic remodeling (P > 0.05). Notably, computed tomography angiography images revealed the expansion of the vascular true lumen and the reduction of the false lumen at three specified levels of the thoracic aorta. The follow-up duration did not show any statistically significant difference between the two groups (10.59 ± 4.52 vs. 9.08 ± 4.35 months, t = 1.561, p = 0.122 > 0.05). Throughout the follow-up period, neither group experienced new endoleaks, spinal cord injuries, nor limb ischemia. In the castor-integrated branch stent group, one patient developed a new distal dissection, prompting further follow-up. Additionally, there was one case of mortality due to COVID-19 in each group. There were no statistically significant differences between the two groups in terms of re-intervention rate and survival rate (P > 0.05).

CONCLUSION

Both 3D printing-assisted extracorporeal pre-fenestration TEVAR and castor-integrated branch stent techniques demonstrate good safety and efficacy in treating Stanford type B aortic dissection with inadequate proximal anchoring. The 3D printing-assisted extracorporeal pre-fenestration TEVAR technique has a lower incidence of postoperative cerebral infarction and beak sign, while the castor-integrated branch stent technique has advantages in operative time.

Efficacy of Endovascular Repair Using Single Left Common Carotid Artery Stent Combined with Castor Single-Branched Stent-Graft in the Treatment of Regional Diseases of Zone 2 of the Aorta

PURPOSE

To observe the short-term efficacy of thoracic endovascular aortic repair (TEVAR) using a single left common carotid artery chimney stent combined with a Castor single-branched stent-graft (SC-TEVAR) in the treatment of zone 2 (Z2) aortic diseases.

MATERIALS AND METHODS

To conduct a retrospective analysis of 20 patients with Z2 aortic diseases who were treated in our department from June 2021 to April 2022. The lesions included true aortic degenerative aneurysms with diameter ≥5.0 cm and penetrating aortic ulcers with depth >1.0 cm or basal width >2.0 cm. All 20 patients accepted the SC-TEVAR treatment, which was a new hybrid method to assure the flow of the left common carotid artery (LCCA) and left subclavian artery (LSA). This method was defined as a concomitant chimney stent for LCCA and a Castor single-branched stent graft for the aorta and LSA. The baseline data and intraoperative data were collected to evaluate the safety and efficacy of this method. The patency of the target blood vessel and any associated complications were evaluated at 1 and 6 months postoperatively, to analyze the safety and efficacy of this new method.

RESULTS

After discharge from the hospital, all patients were followed up by a specific follow-up team. At 6 monthly follow-up period, there were no cardiac events, stroke, hemiplegia, type I endoleak, type II endoleak, proximal stent graft-induced new entries, distal stent graft-induced new entries, wound infection, or bleeding. Only 1 patient developed an inguinal wound hematoma and got conservative treatment. Importantly, no patients developed stenosis or occlusion of the LCCA or LSA. The patency of branched arteries was 100%. The technical success rate was 90%.

CONCLUSION

SC-TEVAR appears to be a new and relatively simple, safe, and effective treatment for Z2 aortic diseases.

CLINICAL IMPACT

This was a single-center retrospective cohort study. A total of 20 patients with zone 2 aortic diseases accepted a new hybrid surgical method named SC-TEVAR. This method was not complicated and could be finished with only 3 peripheral artery exposure. The result showed no mortality, 100% patency of the branch artery, and 90% of technical success in 6 months of follow-up time. SC-TEVAR showed a satisfactory result in this retrospective study and could be promoted as an easy method to treat zone 2 aortic diseases.

Long-Term Outcomes in Thoracic Endovascular Aortic Repair for Complicated Type B Aortic Dissection or Intramural Hematoma Depending on Proximal Landing Zone

Thoracic endovascular aortic repair (TEVAR) is the preferred treatment for complicated type B aortic dissection (TBAD) or intramural hematoma (IMH). This study aimed to investigate the association of the proximal landing zone and its morphology with long-term outcomes in patients with TBAD or IMH. A total of 94 patients who underwent TEVAR for TBAD or IMH between 10/2003 and 01/2020 were included. The cohort was divided according to the proximal landing in Ishimaru zone 2 or 3 and the presence of a healthy landing zone (HLZ; non-dissected or aneurysmatic, ≥2 cm length). Primary outcome was freedom from aortic reintervention. Secondary endpoints were freedom from aortic growth, stroke, spinal cord ischemia, retrograde dissection, proximal stent-graft induced new entry (pSINE), debranching failure, and mortality. Outcomes were assessed using Cox proportional hazard models with mortality as a competing risk. A proximal TEVAR landing in zone 2 was associated with higher rates of reinterventions compared to zone 3 (33% vs. 15%, p = 0.031), spinal cord ischemia (8% vs. 0%, p = 0.037), and pSINE (13% vs. 2%, p = 0.032). No difference was found for the other outcomes, including mortality. Landing in dissected segments was not associated with impaired results. Proximal TEVAR landing in zone 3 may be preferable with regard to long-term aortic reintervention in patients with TBAD or IMH.

A Chinese expert consensus on thoracic endovascular aortic repair of type B aortic dissection with a single-branched stent graft for revascularization of the left subclavian artery

Thoracic endovascular repair (TEVAR) is currently the recommended and most widely used treatment for type B aortic dissection. A major challenge is revascularization of the left subclavian artery in order to extend the landing zone to zone 2 (Ishimaru classification). Various strategies have been used for revascularization, including branched stent graft, fenestrated stent graft, the chimney technique, the parallel technique, and bypass surgery. Single-branched stent graft is one of the most promising strategies, and several products have recently been reported as potential candidates for use with this approach. The Castor single-branched stent graft is the only off-the-shelf product available; this product has been developed through collaboration between Chinese corporations and clinicians. In this Perspective article, clinical experience and data obtained from TEVAR with the Castor single-branched stent graft are summarized by experienced Chinese experts.

Gore TAG thoracic branch endograft for treatment of a subacute type B aortic dissection complicated by rupture

An 80-year-old man presented with a subacute zone 3-5 type B aortic dissection complicated by rupture and visceral and lower extremity malperfusion. He underwent emergent zone 2 repair with a Gore TAG thoracic branch endograft with inclusion of the left subclavian artery for a dominant left vertebral artery. The patient's postoperative course was uncomplicated. Type B aortic dissections can be anatomically complex, and rupture is a rare complication in the subacute phase. We report the novel use of a Gore TAG thoracic branch endograft for the management of type B aortic dissection complicated by rupture and demonstrate its feasibility for patients with type B aortic dissection complicated by rupture.

Timing of Intervention for Aortic Intramural Hematoma

Intramural hematoma (IMH) is one of the acute aortic syndromes along with acute aortic dissection and penetrating aortic ulcer. The three conditions can occur alone or in combination with overlapping presentation. Medical, open surgical, and endovascular treatment is tailored depending on clinical presentation, timing, and location within the aorta. Among patients who present with acute IMH affecting the ascending aorta (Type A), urgent open surgical repair is considered the primary line of treatment in patients who are suitable candidates and unstable. The management of IMH in the descending aorta and aortic arch (Type B) is similar to that applied to treat acute dissections in the same segment. Medical treatment with sequential imaging is recommended in patients with uncomplicated course, and endovascular repair is indicated in patients with rupture, persistent pain, end-organ ischemia, or rapid aortic enlargement. This review discusses the ideal timing for treatment of IMH.

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.

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.