The Impact of Distal Stent Graft–Induced New Entry on Aortic Remodeling of Chronic Type B Dissection

Long-term results of the frozen elephant trunk technique in primary chronic type B aortic dissection

OBJECTIVES

The aim of this study is to analyze long-term results of the total aortic arch replacement with the frozen elephant trunk technique for primary chronic type B aortic dissection.

METHODS

Among 322 patients who had the frozen elephant trunk technique, 43 (13.4%) patients (median age, 64.0 years) with primary chronic type B aortic dissection were analyzed. The patients underwent surgery at a median of 27.0 months after the onset of aortic dissection. The false lumen was patent in 30 (69.8%) patients preoperatively.

RESULTS

Two patients suffered paraplegia and another died of cerebral infarction. Complete thrombosis of the peri-stent false lumen was achieved in 36 (83.7%) patients. Overall survival, freedom from aortic events, and freedom from aortic reintervention were 83.5%, 37.2%, and 42.2% at 5 years, respectively. Survival rates of the patients with or without aortic events were 75.0% and 95.8% at 5 years (Log-rank, p = 0.22). Late aortic events occurred in 19 (44.2%) patients including distal stent graft-induced new entry, type Ib endoleak, and false lumen dilation. The ratio of the stent graft diameter to the preoperative short axis diameter of the true lumen (hazard ratio, 1.90; 95% confidence interval, 1.01-3.59), and the maximal diameter of a postdissection aneurysm (1.07; 1.01-1.12) were the significant multivariate risk predictors of late aortic events.

CONCLUSIONS

Late aortic events occurr fairly frequently, and new strategies need to be explored to enhance the effectiveness of this procedure in the future.

A CT-based predictive model for stent-induced vessel damage: application to type B aortic dissection

OBJECTIVES

The distal stent-induced new entry (distal SINE) is a life-threatening device-related complication after thoracic endovascular aortic repair (TEVAR). However, risk factors for distal SINE are not fully determined, and prediction models are lacking. This study aimed to establish a predictive model for distal SINE based on the preoperative dataset.

METHODS

Two hundred and six patients with Stanford type B aortic dissection (TBAD) that experienced TEVAR were involved in this study. Among them, thirty patients developed distal SINE. Pre-TEVAR morphological parameters were measured based on the CT-reconstructed configurations. Virtual post-TEVAR morphological and mechanical parameters were computed via the virtual stenting algorithm (VSA). Two predictive models (PM-1 and PM-2) were developed and presented as nomograms to help risk evaluation of distal SINE. The performance of the proposed predictive models was evaluated and internal validation was conducted.

RESULTS

Machine-selected variables for PM-1 included key pre-TEVAR parameters, and those for PM-2 included key virtual post-TEVAR parameters. Both models showed good calibration in both development and validation subsamples, while PM-2 outperformed PM-1. The discrimination of PM-2 was better than PM-1 in the development subsample, with an optimism-corrected area under the curve (AUC) of 0.95 and 0.77, respectively. Application of PM-2 in the validation subsample presented good discrimination with an AUC of 0.9727. The decision curve demonstrated that PM-2 was clinically useful.

CONCLUSION

This study proposed a predictive model for distal SINE incorporating the CT-based VSA. This predictive model could efficiently predict the risk of distal SINE and thus might contribute to personalized intervention planning.

CLINICAL RELEVANCE STATEMENT

This study established a predictive model to evaluate the risk of distal SINE based on the pre-stenting CT dataset and planned device information. With an accurate VSA tool, the predictive model could help to improve the safety of the endovascular repair procedure.

KEY POINTS

• Clinically useful prediction models for distal stent-induced new entry are still lacking, and the safety of the stent implantation is hard to guarantee. • Our proposed predictive tool based on a virtual stenting algorithm supports different stenting planning rehearsals and real-time risk evaluation, guiding clinicians to optimize the presurgical plan when necessary. • The established prediction model provides accurate risk evaluation for vessel damage, improving the safety of the intervention procedure.

Predictive factors of distal stent graft-induced new entry after frozen elephant trunk procedure for aortic dissection

OBJECTIVES

The incidence rate of distal stent graft-induced new entry after frozen elephant trunk technique for aortic dissection remains controversial. The aim of this study was to investigate the incidence and seek the clinical and anatomical predictive factors.

METHODS

This study is a retrospective multicenter evaluation of complications including distal stent graft-induced new entry, aortic events, and re-intervention after the frozen elephant trunk procedure for aortic dissection.

RESULTS

Our cohort included total 177 consecutive patients who underwent the frozen elephant trunk procedure for acute and chronic aortic dissection at five centers in Japan from May 2014 to March 2021. The incidence rate of distal stent graft-induced new entry was 14.1% (25/177 patients). The cumulative incidence of d-SINE was 7.1%, 12.4%, 21.4% after 12, 36, and 60 months, respectively. Distal stent graft-induced new entry was not associated with mid-term survival rate. After competing risk regression analysis, onset time > 48 hours (subdistribution hazard ratio, 3.80; 95% confidence interval, 1.13-12.79; P=0.031) was detected as an independent predictor.

CONCLUSIONS

Awareness that there is a relatively higher incidence of distal stent graft-induced new entry after frozen elephant trunk procedures is important. Non-hyperacute phase was detected as an independent risk factor. Preemptive endovascular repair may be appropriate to protect new entry in high-risk patients.

Incidence of Distal Stent Graft Induced New Entry vs. Aortic Remodeling Associated With Frozen Elephant Trunk

Background

The introduction of the frozen elephant trunk (FET) technique for total arch replacement (TAR) has revolutionized the field of aortivascular surgery by allowing hybrid repair of complex aortic pathologies in a single step through combining an open surgical approach with an endovascular one. FET has been associated with favorable aortic remodeling, however, its is also associated with development of distal stent graft induced new entry (dSINE) tears postoperatively. The rate of aortic remodeling and the incidence of dSINE have been linked together, in addition, there seems to be a relationship between these two variables and FET insetion length as well as graft size.

Aims

The scope of this review is to highlight the rate of aortic remodeling as well the incidence of dSINE associated with different FET devices available commercially. This review also aimed to investigate the relationship between aortic remodeling, dSINE, FET insertion length and FET graft size.

Methods

We conducted a comprehensive literature search using multiple electronic databases including PubMed, Ovid, Scopus and Embase in order to collate all research evidence on the above mentioned variables.

Results

Thoraflex™ Hybrid Plexus seems to yield optimum aortic remodeling by promoting maximum false thrombosis as well true lumen expansion. Thoraflex Hybrid™ is also associated with the lowest incidence of dSINE post-FET relative to the other FET devices on the market. Aortic remodeling and dSINE do influence each other and are both linked with FET graft length and size.

Conclusion

The FET technique for TAR shows excellent aortic remodeling but is associated with a considerable risk of dSINE development. However, Thoraflex™ Hybrid has demonstrated itself to be the superior FET device on the aortic arch prostheses market. Since aortic remodeling, dSINE, FET insertion length and stent graft size are all interconnect, the choice of FET device length and size must be made with great care for optimum results.

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.

Thoracic endovascular repair of chronic type B aortic dissection: a systematic review

BACKGROUND

At present, the optimal management strategy for chronic type B aortic dissection (CTBAD) remains unknown, as equipoise remains regarding medical management versus endovascular treatment versus open surgery. However, the results over recent years of thoracic endovascular aortic repair (TEVAR) in CTBAD appear promising. The aim of this systematic review was to provide a comprehensive analysis of the available data reporting outcomes and survival rates for TEVAR in CTBAD.

METHODS

Electronic searches of six databases were performed from inception to April 2021. All studies reporting outcomes, specifically 30-day mortality rates, for endovascular repair of CTBAD were identified. Relevant data were extracted, and a random-effects meta-analysis of proportions or means was performed to aggregate the data. Survival data were pooled using data derived from original Kaplan-Meier curves, which allows reconstruction of individual patient data.

RESULTS

Forty-eight studies with 2,641 patients were identified. Early (<30 days) all-cause and aortic-related mortality rates were low at 1.6% and 0.5%, respectively. Incidence of retrograde type A dissection in the post-operative period was only 1.4%. There were also low rates of cerebrovascular accidents and spinal cord injury (1.1% and 0.9%, respectively). Late follow-up all-cause mortality was 8.0%, however, late aortic-related mortality was only 2.4%. Reintervention rates were 10.1% for endovascular and 6.7% for surgical reintervention. Pooled rates of overall survival at 1-, 3-, 5- and 10-year were 91.5%, 84.7%, 77.7% and 56.3%, respectively.

CONCLUSIONS

The significant heterogeneity in the available evidence and absence of consensus reporting standards are important considerations and concern when interpreting the data. Evaluation of the evidence suggests that TEVAR for CTBAD is a safe procedure with low rates of complications. However, the optimal treatment strategy for CTBAD remains debatable and requires further research. Evidence from high-quality registries and clinical trials are required to address these challenges.

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.

A S-Shaped Association of Distal Oversizing Ratio with Distal Stent-Graft-Induced New Entry Following Thoracic Endovascular Aortic Repair for Stanford B Aortic Dissection

BACKGROUND

This study was performed to evaluate the nonlinear association of the distal oversizing ratio with distal stent-graft-induced new entry (dSINE) following thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD) and to find the optimal value of the distal oversizing ratio for prevention strategy of dSINE.

METHODS

Total of 177 patients who underwent TEVAR for TBAD from the Registry Of type B aortic dissection with the Utility of STent graft were retrospectively investigated. Patients were stratified into two groups on the median distal oversizing ratio: lower group (≤16%, n = 88) and higher group (>16%, n = 89). The Kaplan-Meier method was used to estimate the cumulative incidence of dSINE. The multivariate Cox proportional hazards model was used to identify the association of the distal oversizing ratio with dSINE. Restricted cubic smoothing spline plots and two-piecewise regression were used to analyze the possible nonlinear association.

RESULTS

Eleven patients developed dSINE (6.21%) during the median follow-up time of 12.37 months (interquartile range, 8.07-18.17 months). An S-shaped association of the distal oversizing ratio with dSINE was identified. When the distal oversizing ratio was ≤40%, the risk of dSINE increased with distal oversizing ratio, and the risk of dSINE was highest when the distal oversizing ratio reached 40% (adjusted HR, 1.09; 95% CI, 1.02-1.17; P = 0.011). A larger distal oversizing ratio over 40% did not generate a greater risk of dSINE (adjusted HR, 0.95; 95% CI, 0.87-1.05; P = 0.455).

CONCLUSIONS

This study substantiated previous findings that the dSINE was associated with the increasing distal oversizing ratio. We also found an S-shaped association between the distal oversizing ratio and dSINE after TEVAR for TBAD. The distal oversizing ratio of 40% can be used for stratified management of patients who underwent TEVAR for TBAD.

Midterm outcomes of fenestrated TEVAR using physician-modified endovascular grafts for zone 2

OBJECTIVES

To summarize the experience and midterm outcomes of physician-modified endovascular grafts for zone 2 thoracic endovascular aortic repair.

METHODS

A retrospective analysis was conducted of 51 consecutive patients (mean age 57.6 ± 12.5 years, 39 males) treated with thoracic endovascular aortic repair using physician-modified endovascular grafts for reconstructing the left subclavian artery from November 2015 to December 2019. The primary endpoints during follow-up were the overall mortality, aorta-related mortality, and major complications. The secondary endpoints were reintervention and the patency of the target branches, the demographics and technical details were also described and analyzed.

RESULTS

Sixty-three thoracic stent-grafts were deployed in 51 patients and emergency surgery was performed in 10 patients (19.6%). Technical success was 94.1% (48/51). The incidence of perioperative complications was 15.7%, and the 30-day mortality was 0%. At a mean follow-up of 42.0 ± 14.4 months (range, 14-63 months), all the left subclavian arteries remained patent. All-cause mortality was 3.9% (2/51) and not aorta-related deaths. Estimated survival at one and three years was 98.0 ± 1.9% and 96.0 ± 2.8%, respectively.

CONCLUSIONS

The physician-modified endovascular grafts is feasible and effective to preserve left subclavian artery in thoracic endovascular aortic repair for aortic arch pathologies with unhealthy proximal landing zone.

Outcomes of open repairs of chronic distal aortic dissection anatomically amenable to endovascular repairs

OBJECTIVE

To review short-term outcomes and long-term survival and durability after open surgical repairs for chronic distal aortic dissections in patients whose anatomy was amenable to thoracic endovascular aortic repair (TEVAR).

METHODS

Between February 1991 and August 2017, we repaired chronic distal dissections in 697 patients. Of those patients, we enrolled 427 with anatomy amenable to TEVAR, which included 314 descending thoracic aortic aneurysms (DTAAs) and 105 extent I thoracoabdominal aortic aneurysms (TAAAs). One hundred eighty-five patients (44%) had a history of type A dissection, and 33 (7.9%) had a previous DTAA/TAAA repair. Variables were assessed with logistic regression for 30-day mortality and Cox regression for long-term mortality. Time-to-event analysis was performed using Kaplan-Meier methods.

RESULTS

Thirty-day mortality was 8.4% (n = 36). In all, 22 patients (5.2%) developed motor deficit (paraplegia/paraparesis), and 17 (4.0%) experienced stroke. Multivariable analysis identified low estimated glomerular filtration rate (eGFR; <60 mL/min/1.73 m²), previous DTAA/TAAA repair, and chronic obstructive pulmonary disease (COPD) as associated with 30-day mortality. Patients without all 3 risk factors had a 30-day mortality rate of 2.6%. During a median follow-up of 6.5 years, 160 patients died. The survival rate was 81% at 1 year and 61% at 10 years. Cox regression analysis identified preoperative aortic rupture, eGFR <60 mL/min/1.73 m², previous DTAA/TAAA repair, COPD, and age >60 years as predictive of long-term mortality. Forty-five patients required subsequent aortic procedures, including 8 reinterventions to the treated segment. Freedom from any aortic procedures was 85% at 10 years, and aortic procedure-free survival was 45% at 10 years. Hereditary aortic disease was the sole predictor for any aortic interventions (hazard ratio, 3.2; P = .004).

CONCLUSIONS

Open surgical repair provided satisfactory low neurologic complication rates and durable repairs in chronic distal aortic dissection. Patients without low eGFR, redo, and COPD are the low-risk surgical candidates and may benefit from open surgical repair at centers with similar experience to ours. Patients with hereditary aortic disease warrant close surveillance.

Endovascular Repair of Postdissection Aortic Aneurysms Using Physician-Modified Endografts

BACKGROUND

The purpose of this study was to report our experience and evaluate the technical and clinical outcomes of physician-modified endovascular aortic repair of chronic postdissection thoracoabdominal aortic aneurysms.

METHODS

A retrospective analysis of prospectively collected data of consecutive patients presenting with chronic postdissection aneurysms unfit for open surgery and treated by physician-modified stent grafts between January 2016 and December 2019 was conducted. Outcome data were collected retrospectively. Early outcomes included technical success, perioperative mortality, and major adverse events. Late outcomes included reintervention, false lumen thrombosis rate, aneurysm size regression, and survival.

RESULTS

Sixty-two patients (80.1% men with a mean age of 64 ± 9.9 years) were treated. The technical success was 98.3%. There was 1 (1.6%) death within 30 days. Perioperative major adverse events included respiratory failure (1.6%), spinal cord injury (0%), acute kidney injury (3.2%; 1 dialysis), bowel ischemia (1.6%), myocardial infarction (1.6%), and lower limb ischemia (1.6%). A reintervention was required in 6 (9.8%) patients. The false lumen thrombosis rates were 91.8% (n = 45 of 49) at 1-year follow-up. One patient died during follow-up from an aneurysm-related cause. The estimated overall survival rates were 98.4% and 96.8% at 6 months and 12 months, respectively.

CONCLUSIONS

The report confirmed the feasibility and safety of fenestrated and branched endovascular aortic repair in the setting of postdissection thoracoabdominal aortic aneurysms. Despite the associated perioperative risk and high probability of intended or unintended reintervention, the procedure could lead to favorable aortic remodeling.

Relevance of Aortic Dissection Chronicity to the Development of Stent Graft-induced New Entry

BACKGROUND

The relevance of aortic dissection chronicity to the development of stent graft-induced new entry (SINE) is unknown.

METHODS

This study enrolled 69 patients who underwent thoracic endovascular aortic repair (TEVAR) for chronic aortic dissection from January 2006 to December 2017 and were followed up for ≥6 months. Their medical records were reviewed retrospectively. Patients were stratified according to TEVAR timing into an early group (≤6 months from the onset of aortic dissection) and a late group (>6 months after the onset). The incidence of SINE as well as the interval between TEVAR and the development of SINE was compared between these groups.

RESULTS

During the follow-up period, SINE occurred in 12% (3/26) and 35% (15/43) of patients in the early and late groups, respectively (P = .029). The interval between TEVAR and SINE development was significantly longer in the late group than the early group (median, 92 days vs 1144 days, respectively; P = .002). According to the multivariate analysis results, the late group (hazard ratio, 3.667; 95% confidence interval, 1.037-12.968; P = .044) and the distal oversizing ratio (hazard ratio, 1.492; 95% confidence interval, 1.071-2.080; P = .018) were the independent predictors for SINE development.

CONCLUSIONS

TEVAR should be performed in the early period of the chronic phase to prevent SINE. Close and lifelong follow-up is mandatory for patients who undergo TEVAR >6 months after onset because SINE can develop several years after TEVAR in those patients.

Mid-Term Results of Frozen Elephant Trunk Technique for Chronic Aortic Dissection

Objective: In this study, we report our experience using the frozen elephant trunk (FET) technique for chronic aortic dissection. Methods: Between January 2011 and December 2017, 15 patients underwent total arch replacement (TAR) with the FET technique for chronic aortic dissection (CAD). Results: Hospital mortality was 6.7% (n=1). No patients experienced spinal cord injury. Distal stent-induced new entry (dSINE) occurred in the early postoperative period in one patient. There were four unplanned additional operations to manage dSINE. Five patients suffered from dSINE, and aortoesophageal fistula developed in three of them. Short insertion length of the FET and large angle between the distal edge of the FET and the descending aorta were significantly more common in the dSINE group than in the non-dSINE group. The cumulative survival rates at 1, 3, and 5 years were 93.3%, 93.3%, and 66.4%, respectively. The cumulative aortic event-free rates at 1, 2, and 3 years were 85.7%, 77.1%, and 52.9%, respectively. Conclusion: The FET technique for CAD provided good early results. Short insertion length of the FET, however, can induce dSINE, which requires an additional operation at mid-term. Thus, surgical indication of the FET technique for CAD must be discussed.

Location of Reentry Tears Affects False Lumen Thrombosis in Aortic Dissection Following TEVAR

Purpose: To report a study that assesses the influence of the distance between the distal end of a thoracic stent-graft and the first reentry tear (SG-FRT) on the progression of false lumen (FL) thrombosis in patients who underwent thoracic endovascular aortic repair (TEVAR). Materials and Methods: Three patient-specific geometrical models were reconstructed from postoperative computed tomography scans. Two additional models were created by artificially changing the SG-FRT distance in patients 1 and 2. In all 5 models, computational fluid dynamics simulations coupled with thrombus formation modeling were performed at physiological flow conditions. Predicted FL thrombosis was compared to follow-up scans. Results: There was reduced false lumen flow and low time-averaged wall shear stress (TAWSS) in patients with large SG-FRT distances. Predicted thrombus formation and growth were consistent with follow-up scans for all patients. Reducing the SG-FRT distance by 30 mm in patient 1 increased the flow and time-averaged wall shear stress in the upper abdominal FL, reducing the thrombus volume by 9.6%. Increasing the SG-FRT distance in patient 2 resulted in faster thoracic thrombosis and increased total thrombus volume. Conclusion: The location of reentry tears can influence the progression of FL thrombosis following TEVAR. The more distal the reentry tear in the aorta the more likely it is that FL thrombosis will occur. Hence, the distal landing zone of the stent-graft should be chosen carefully to ensure a sufficient SG-FRT distance.

Society for Vascular Surgery (SVS) and Society of Thoracic Surgeons (STS) Reporting Standards for Type B Aortic Dissections

This Society for Vascular Surgery/Society of Thoracic Surgeons (SVS/STS) document illustrates and defines the overall nomenclature associated with type B aortic dissection. The contents describe a new classification system for practical use and reporting that includes the aortic arch. Chronicity of aortic dissection is also defined along with nomenclature in patients with prior aortic repair and other aortic pathologic processes, such as intramural hematoma and penetrating atherosclerotic ulcer. Complicated vs uncomplicated dissections are clearly defined with a new high-risk grouping that will undoubtedly grow in reporting and controversy. Follow-up criteria are also discussed with nomenclature for false lumen status in addition to measurement criteria and definitions of aortic remodeling. Overall, the document provides a facile framework of language that will allow more granular discussions and reporting of aortic dissection in the future.

Two-stage repair of DeBakey type IIIb aneurysm, using total arch replacement

Background

Open repair for chronic DeBakey type IIIb dissecting aortic aneurysm is an invasive procedure involving open proximal anastomosis under hypothermic cardiac arrest, with significant morbidity in high-risk patients. We adopted a two-stage repair strategy using total arch replacement with the elephant trunk technique, which enables aortic crossclamping and avoids open proximal anastomosis at the second-stage graft replacement through a left thoracotomy.

Methods

From January 2008 to October 2018, we performed DeBakey type IIIb dissecting aortic aneurysm repair in 76 cases, and compared the results of two-stage repair (group 1, 25 cases) and single-stage repair using graft replacement with open proximal anastomosis through a left thoracotomy (group 2, 31 cases).

Results

In group 1, the elephant trunk technique was successful in all cases. The second intervention included endovascular repair (13 cases) and graft replacement through a left thoracotomy (7 cases). Five cases were followed up conservatively because the false lumen was thrombosed after the elephant trunk technique. Aorta-related adverse events were seen in 5 cases in group 1 (1 re-dissection, 1 rupture, 2 stent-graft-induced new entries, 1 stent-graft migration) and 6 in group 2 (1 additional thoracic endovascular aortic repair, 1 rupture, 4 acute type A aortic dissections). There were no statistical differences between the two groups regarding aorta-related adverse events and death. The postoperative course was acceptable in both groups.

Conclusions

Single-stage repair with open proximal anastomosis is an option in patients not at high risk for invasive surgery, while two-stage repair is recommended for high-risk patients.

The Role of Thoracic Endovascular Repair in Chronic Type B Aortic Dissection

Continued device improvements along with refined implantation techniques have revolutionize the use of thoracic endovascular repair for both aortic dissections and aneurysms. This is now considered standard of care for acute, complicated type B aortic dissection in patients with appropriate anatomy. However, the treatment of chronic, uncomplicated type B dissection continues to present challenges for the aortic surgeon, as the long-held dogma of medical management and surveillance for aneurysm degeneration has recently come into questions. We present evidence for a more thoughtful approach to management and intervention with thoracic endovascular repair in select patients with chronic, type B dissection.

Intravascular ultrasound assisted sizing in thoracic endovascular aortic repair improves aortic remodeling in Type B aortic dissection

The precise sizing of the stent graft in thoracic endovascular aortic repair (TEVAR) affects aortic remodeling and hence, further outcome. Covering the proximal entry tear is essential for successful treatment of Type B aortic dissection. Intravascular ultrasound (IVUS) enables real-time aortic diameter assessment, and is especially useful when computed tomography (CT) image quality is poor. IVUS, however, is not routinely utilized due to cost inefficiency. We investigated the impact of IVUS-assisted stent graft sizing on aortic remodeling in TEVAR. In this single-center retrospective study we evaluated patients with Type B aortic dissection undergoing both CT and IVUS before TEVAR. We assessed the aortic diameter at the level of the left subclavian artery via both methods before stent implantation and analyzed due to which method the implanted stent graft was chosen, retrospectively. To determine the degrees of aortic remodeling involved, we evaluated true lumen and false lumen diameters, and total aortic remodeling in CT. We analyzed 45 patients with Type B aortic dissection undergoing TEVAR. The mean ages were 66.9±10.0 years fo0072 IVUS (n = 20) and 62.3±14.2 years for CT-assisted TEVAR (n = 25; p = 0.226). The follow-up time for both groups did not differ between the two groups (IVUS: 22.9±23.1 months, CT: 25.6±23.0 months; p = 0.700). While both methods were associated with advantages regarding aortic remodeling, IVUS-assisted sizing yielded a greater increase in true lumen (30.4±6.2 vs. 25.6±5.3; p = 0.008) and reductions in false lumen (14.4±8.5 vs. 23.9±9.3; p = 0.001) and total aortic diameter (35.5±6.0 vs. 39.9±8.1; p = 0.045). IVUS-guided stent graft sizing in Type B aortic dissection shows beneficial effects on aortic remodeling and might be of additional advantage in aortic diseases, especially when CT image quality is poor.