Anatomic feasibility of the investigational GORE EXCLUDER Thoracoabdominal Branch Endoprosthesis (TAMBE), off-the-shelf multibranched endograft for the treatment of pararenal and thoracoabdominal aortic aneurysms

Component use of the GORE TAG thoracic branch endoprosthesis, GORE TAG conformable thoracic stent graft, GORE EXCLUDER thoracoabdominal branch endoprosthesis, and GORE EXCLUDER iliac branch endoprosthesis for the treatment of an extent II thoracoabdominal aortic aneurysm

We report the first published component use of the GORE TAG thoracic branch endoprosthesis, GORE TAG conformable thoracic stent graft, GORE EXCLUDER thoracoabdominal branch endoprosthesis (TAMBE), and GORE EXCLUDER iliac branch endoprosthesis together in a 77-year-old woman who underwent repair of an extent II thoracoabdominal aortic aneurysm. The retrograde left subclavian artery branch portal of the GORE TAG thoracic branch endoprosthesis was used to facilitate fenestrated-branched endovascular repair in this case.

Operative times and outcomes of complex endovascular repairs of thoracoabdominal aneurysms

BACKGROUND

Owing to the significant morbidity and mortality of open thoracoabdominal aortic aneurysm surgery, complex endovascular repairs have become increasingly common, but still carry substantial risk. These repairs require large-bore access, with resultant pelvic and lower extremity ischemia. We, therefore, hypothesized that operative timing would be associated with outcomes, because efficient surgery would limit the ischemic time as well as anesthesia time.

METHODS

We studied all thoracoabdominal aortic aneurysm surgerywith complex endovascular repairs (Crawford types 1, 2, 3, and 5) incorporating at least one branch vessel from 2014 to 2021 in the Vascular Quality Initiative and categorized them into quartiles of total operating time. To account for variations in case complexity and intraoperative events, we performed a subanalysis stratifying each surgeon by their median operating time. Multilevel logistic regression was used to compare perioperative outcomes including mortality, thoracoabdominal life-altering events (a composite of perioperative death, stroke, permanent paralysis and/or dialysis), spinal cord ischemia (SCI), acute kidney injury, major adverse cardiac events, myocardial infarction, and dialysis.

RESULTS

There were 2925 thoracoabdominal aortic aneurysm surgery with complex endovascular repairs during the study period. Procedure times ranged from <204 minutes in the first quartile to >365 minutes in the fourth. Longer cases more commonly involved older patients who were more often female and higher rates of prior stroke and preoperative anemia. They involved larger, more extensive aneurysms, with higher rates of prior aortic surgery, and more commonly used physician-modified endografts or parallel grafting to incorporate more branch vessels. In addition, they were less often staged procedures, and used more spinal drains, femoral cutdowns, and upper extremity access. Operating time decreased as experience increased. In adjusted analyses, the odds of mortality and every morbidity studied increased stepwise with operating time, with 4- to 13-fold higher odds in the highest quartiles. SCI had the strongest association with procedure times, with seven-fold higher odds (odds ratio, 7.2; 95% confidence interval, 2.9-17.9; P < .001) of any SCI in the highest quartile compared to the lowest, and 13-fold higher odds of permanent SCI (OR, 13.1; 95% confidence interval, 3.9-44.7; P < .001). These results were consistent when surgeons were grouped into quartiles by their median operating times. Medium-term mortality was also higher in the upper quartile of operating time (hazard ratio, 2.7; 95% confidence interval, 1.4-5.1; P = .002).

CONCLUSIONS

Longer operating times for complex thoracoabdominal aortic aneurysm surgerywith complex endovascular repairs were associated with markedly higher rates of morbidity and mortality, especially SCI. These results emphasize the importance of expeditious repairs by experienced teams.

Surgeon volumes of endovascular thoracoabdominal aneurysm repairs, but not juxtarenal repairs, are associated with outcomes following endovascular repair of thoracoabdominal aneurysms

OBJECTIVE

Endovascular thoracoabdominal aortic aneurysm (eTAAA) repair remains one of the more technically challenging aspect of vascular surgery, with significant risk of mortality, spinal cord ischemia, and end organ damage. Although fenestrated devices are available for juxtarenal aneurysms, there are no commercially available eTAAA devices on the United States market currently. We therefore studied how the volume of juxtarenal repairs would translate to outcomes of these more complicated aneurysms.

METHODS

We studied all eTAAA repairs (Crawford type 1-3) in the Vascular Quality Initiative from 2014 to 2021 and categorized surgeons into quartiles based on their average annual eTAAA volume and endovascular juxtarenal volume. Our primary outcome was thoracoabdominal life altering events (composite of perioperative death, stroke, permanent spinal cord ischemia, and dialysis). We employed mixed effects logistic regression clustering by center and surgeon.

RESULTS

We identified 5335 repairs from 607 surgeons, with annual average eTAAA volumes of 2629 from 400 surgeons. Quartile 1 involved less than two repairs and quartile 4 involved >12 repairs per year. Repairs at higher quartiles were for larger aneurysms, more commonly employed staged repairs, utilized spinal drains, and more frequently utilized physician-modified endografts, whereas low-volume surgeons most commonly employed parallel grafting. Higher volume surgeons had overall shorter procedural times, fluoroscopy time, and less total contrast. Technical success similarly increased as procedure volume increased. In adjusted analyses, rates of perioperative death, thoracoabdominal life altering events, stroke, acute kidney injury, and major adverse cardiac events were all lower in the highest volume quartile compared with the lowest. However, after accounting for eTAAA volume, surgeon volume of endovascular juxtarenal repairs was not associated with any postoperative outcome, and there was no significant interaction between juxtarenal and eTAAA volume. Medium-term mortality was lowest in patients treated in the top two quartiles of volume (hazard ratio, 0.77; 95% confidence interval, 0.61-0.97; P = .024).

CONCLUSIONS

Surgeon eTAAA experience shows a strong volume-outcome effect on outcomes in the immediate post operative period and in permanent patient-centered outcomes. However, experience in less extensive aneurysms did not directly translate to thoracoabdominal aneurysms. Further study is needed to evaluate the role that commercial graft availability and repair type contributes to these findings.

Development of a method to achieve antegrade in situ fenestration of endovascular stent grafts in abdominal aortic aneurysms

Abdominal aortic aneurysm (AAA) is the focal dilation of the terminal aorta, which can lead to rupture if left untreated. Traditional endovascular aneurysm repair techniques are minimally invasive and pose low mortality rates compared with open surgical repair; however, endovascular aneurysm repair procedures face challenges in accommodating variations in the patient's anatomy. Complex aneurysms are defined when the sac extends past the renal arteries or has an insufficient neck landing zone to deploy a traditional endograft. Fenestrated endografts were introduced to enable the repair of complex aneurysms by the creation of fenestrations to enable blood flow into the visceral arteries. This study investigates proof of concept for creating antegrade in situ fenestrations of off-the-shelf endografts using a novel endovascular orifice detection device. Our technique enables the precise location of the visceral artery orifices using fiber optic cables and an infrared light source. The endovascular orifice detection device was tested rigorously in precisely locating an artery opening in blood and a custom AAA phantom model. The study also explored the safest means of creating a fenestration using mechanical puncture and a laser. This innovative approach offers a viable alternative for patients with complex AAAs.

Three-year outcomes of off-the-shelf Gore thoracoabdominal multibranch endoprosthesis and physician-modified endografts for complex abdominal and thoracoabdominal aortic aneurysms

OBJECTIVE

Fenestrated-branched endovascular aortic repair (FB-EVAR) has shown favorable outcomes for repair of complex aneurysms and thoracoabdominal aortic aneurysms. Physician-modified endografting (PMEG) and the Gore thoracoabdominal multibranch endoprosthesis (TAMBE) provide custom and off-the-shelf devices for FB-EVAR, respectively. This study compares the outcomes of TAMBE and PMEG at a single institution.

METHODS

A retrospective review of patients who underwent TAMBE as part of the multicenter pivotal trial or PMEG as part of a prospective physician-sponsored investigational device exemption at a single institution between 2020 and 2022 were completed. Patient demographics, characteristics, and perioperative and midterm outcomes were compared.

RESULTS

A total of 68 patients were included, with 12 in the TAMBE group and 56 in the PMEG group. Baseline characteristics were comparable between groups. Aneurysm type was most often thoracoabdominal aortic aneurysm in both groups (58% TAMBE and 52% PMEG). TAMBE had a higher rate of upper extremity access (100% vs 63%; P = .013) and longer mean procedure time (247 ± 36 minutes vs 189 ± 49 minutes; P < .001). Other intraoperative metrics were similar between groups. Technical success was 100% in TAMBE and 95% in PMEG (P = .412). There was no 30-day mortality in either group. No major adverse events occurred with TAMBE, whereas in PMEG cases, 2% had respiratory failure, 2% required dialysis, and 4% experienced spinal cord ischemia. Although the overall endoleak rates were similar (50% of TAMBE vs 41% of PMEG; P = .57), type II endoleaks accounted for all of the endoleaks in the TAMBE group, whereas type I or III endoleaks were seen in 11% of PMEG patients. At a median follow-up of 26.7 months for the TAMBE group and 21.2 months for the PMEG group, target vessel instability was seen in 10.4% of TAMBE, and 6.9% of PMEG targeted branches (P = .401). Reintervention was required in 33% of TAMBE patients and 27% of PMEG patients (P = .646). Estimated freedom from reintervention rates at 3 years were similar (56% TAMBE vs 62% PMEG, log-rank P = .910). Freedom from visceral renal target vessel instability at 3 years was 89% for both groups (log-rank P = .459). The Kaplan-Meier 3-year estimated survival was 100% for patients in the TAMBE group and 77% for patients in the PMEG group (log-rank P = .157).

CONCLUSIONS

At experienced centers, FB-EVAR can be completed with PMEG or TAMBE with comparable, excellent perioperative and midterm outcomes. Reinterventions are frequently needed for both TAMBE and PMEG.

A national census for the off-label treatment of complex aortic aneurysms

OBJECTIVE

Despite regulatory challenges, device availability, and rapidly expanding techniques, off-label endovascular repair of complex aortic aneurysms (cAAs) has expanded in the past decade. Given the lack of United States Food and Drug Administration-approved endovascular technology to treat cAAs, we performed a national census to better understand volume and current practice patterns in the United States.

METHODS

Targeted sampling identified vascular surgeons with experience in off-label endovascular repair of cAAs. An electronic survey was distributed with institutional review board approval from the University of Rochester to 261 individuals with a response rate of 38% (n = 98).

RESULTS

A total of 93 respondents (95%) reported off-label endovascular repair of cAAs. Mean age was 45.7 ± 8.3 years, and 84% were male. Most respondents (59%) were within the first 10 years of practice, and 69% trained at institutions with a high-volume of off-label endovascular procedures for complex aortic aneurysms with or without a physician-sponsored investigational device exemption (PS-IDE). Twelve respondents from 11 institutions reported institutional PS-IDEs for physician-modified endografts (PMEGs), in-situ laser fenestration (ISLF), or parallel grafting technique (PGT), including sites with PS-IDEs for custom-manufactured devices. Eighty-nine unique institutions reported elective off-label endovascular repair with a mean of 20.2 ± 16.5 cases/year and ∼1757 total cases/year nationally. Eighty reported urgent/emergent off-label endovascular repair with a mean of 5.7 ± 5.4 cases/year and ∼499 total cases/year nationally. There was no correlation between high-volume endovascular institutions (>15 cases/year) and institutions with high volumes of open surgical repair for cAAs (>15 cases/year; odds ratio, 0.7; 95% confidence interval, 0.3-1.5; P = .34). Elective techniques included PMEG (70%), ISLF (30%), hybrid PMEG/ISLF (18%), and PGT (14%), with PMEG being the preferred technique for 63% of respondents. Techniques for emergent endovascular treatment of complex aortic disease included PMEG (52%), ISLF (40%), PGT (20%), and hybrid-PMEG/ISLF (14%), with PMEG being the preferred technique for 41% of respondents. Thirty-nine percent of respondents always or frequently offer referrals to institutions with PS-IDEs for custom-manufactured devices. The most common barrier for referral to PS-IDE centers included geographic distance (48%), longitudinal relationship with patient (45%), and costs associated with travel (33%). Only 61% of respondents participate in the Vascular Quality Initiative for complex endovascular aneurysm repair, and only 57% maintain a prospective institutional database. Eighty-six percent reported interest in a national collaborative database for off-label endovascular repair of cAA.

CONCLUSIONS

Estimates of off-label endovascular repair of cAAs are likely underrepresented in the literature based on this national census. PMEG was the most common technique for elective and emergent procedures. Under-reported off-label endovascular repair of cAA outcomes data appears to be limited by non-standardized PS-IDE reporting to the United States Food and Drug Administration, and the lack of Vascular Quality Initiative participation and prospective institutional data collection. Most participants are interested in a national collaborative database for endovascular repair of cAAs.

Independent associations with early mortality after open repair of Crawford extent IV thoracoabdominal aortic aneurysms

OBJECTIVE

We aimed to identify outcomes and factors that independently associate with early mortality after open repair of Crawford extent IV thoracoabdominal aortic aneurysms, defined as aneurysms confined to the segment below the diaphragm.

METHODS

This retrospective analysis included 721 extent IV thoracoabdominal aortic aneurysm repairs performed in our institution from 1986 to 2021. Indications for repair were aneurysm without dissection in 627 cases (87.0%) and aortic dissection in 94 cases (13.0%). Overall, 466 patients (64.6%) were symptomatic preoperatively; 124 (17.2%) procedures were performed in patients with acute presentation, including 58 (8.0%) ruptured aneurysms.

RESULTS

Operative death occurred after 49 (6.8%) repairs. Persistent renal failure necessitating dialysis occurred after 43 (6.0%) repairs. Binary logistic regression modeling revealed that previous extent II thoracoabdominal aortic aneurysm repair, chronic kidney disease, previous myocardial infarction, urgent or emergency repair, and longer crossclamp times during surgery were independently associated with operative mortality. Among early survivors (n = 672), competing risk analysis revealed that cumulative incidence of mortality and reintervention rates at 10 years were 74.8% (95% confidence interval, 71.4%-78.5%) and 3.3% (95% confidence interval, 2.2%-5.1%), respectively.

CONCLUSIONS

Although patient comorbidities contributed to operative mortality, factors associated with the repair, such as urgent or emergency status, the duration of aortic crossclamping, and certain types of complex reoperation, also played prominent roles. Patients who survive the operation can expect a durable repair that usually is free from late reintervention. Expanding our collective knowledge regarding patients who undergo open repair of extent IV thoracoabdominal aortic aneurysms will enable clinicians to establish best practices and improve patient outcomes.

National trends in utilization of surgeon-modified grafts for complex and thoracoabdominal aortic aneurysms

INTRODUCTION

Custom-branched/fenestrated grafts are widely available in other countries, but in the United States, they are limited to a handful of centers, with the exception of a 3-vessel juxtarenal device (ZFEN). Consequently, many surgeons have turned to alternative strategies such as physician-modified endografts (PMEGs). We therefore sought to determine how widespread the use of these grafts is.

METHODS

We studied all complex endovascular repairs of complex and thoracoabdominal aortic aneurysms in the Vascular Quality Initiative from 2014 to 2022 to examine temporal trends.

RESULTS

A total of 5826 repairs were performed during the study period: 1895 ZFEN, 3241 PMEG, 595 parallel grafting, and 95 where parallel grafting was used in addition to ZFEN, with a mean of 2.7 ± 0.98 vessels incorporated. Over time, the number of PMEGs steadily increased, both overall and for juxtarenal aneurysms, whereas the number of ZFENs essentially leveled off by 2017 and has remained steady ever since. In the most recent complete year (2021), PMEGs outnumbered ZFENs by over 2:1 overall (567 to 256) and nearly twofold for juxtarenal repairs. In three-vessel cases involving juxtarenal aneurysms, PMEGs were used as frequently as ZFENs (43% vs 43%), whereas the proportion of juxtarenal aneurysms repaired using a four-vessel graft configuration increased from 20% in 2014 to 29% in 2021 (P < .001). The differences in PMEG use were more pronounced as surgeon volume increased. Surgeons in the lowest quartile of volume performed <2 complex repairs annually, evenly split between PMEGs and ZFENs. However, surgeons in the highest quartile of volume performed a median of 18 (interquartile range: 10-21) PMEGs/y, but only 1.6 (interquartile range: 0.8-3.4) ZFENs/y. The number of physician-sponsored investigational device exemption trials of PMEGs has expanded from 1 in 2012 to 8 currently enrolling. As those data are not included in the Vascular Quality Initiative, the true number of PMEGs is likely substantially higher.

CONCLUSIONS

PMEGs have become the dominant endovascular repair modality of complex abdominal and thoracoabdominal aortic aneurysms outside of investigational device exemptions. The field of endovascular aortic surgery and patients with complex aneurysms would benefit from broader publication of PMEG techniques, outcomes, and comparisons to custom-manufactured grafts.

Off the Shelf Multibranched Endograft for Thoraco-Abdominal and Pararenal Abdominal Aortic Aneurysms: a Prospective, Single Centre Study of the G-Branch Endograft

OBJECTIVE

To investigate outcomes of a novel, off the shelf multibranched endovascular stent graft for the treatment of thoraco-abdominal aortic aneurysm (TAAA) and pararenal abdominal aortic aneurysm (PAAA).

METHODS

A prospective, single centre study including 15 patients (mean age, 63.4 ± 10.7 years; 13 male) with TAAA or PAAA treated from October 2019 to March 2021 with a G-Branch endograft (Lifetech Scientific, Shenzhen, China) featuring a mixed multibranch design with two inner and two outer branches for reconstruction of the visceral and bilateral renal arteries, respectively. Follow up assessments were scheduled before discharge and at 30 days, six and 12 months after the index procedure. Annual telephone interviews were performed beyond the initial 12 months. The Kaplan-Meier method was used to estimate cumulative mortality and morbidity rates after endovascular repair.

RESULTS

Technical success was achieved in all 15 patients. Nine patients (60%) had TAAA and six (40%) had PAAA (mean maximum aneurysm diameter, 73.7 ± 15.8 mm). The median follow up was 31.4 months (range, 10.1 - 44.0 months). At 30 days, there was no death and 7% morbidity (one case of temporary spinal cord ischaemia on Day 4). At one year, the mortality rate was 7% (one death from stroke at 10 months) and morbidity was 13% (one other case of renal function decline at six months). There were no aneurysm dilatations, re-interventions, or access related complications, and two (13%) persistent type II endoleaks. The one year primary branch patency rate was 100% for the four renovisceral arteries in all 13 patients who underwent computed tomography examinations. One patient died of hepatocellular carcinoma 29 months post-operatively, resulting in an estimated three year mortality rate of 13%.

CONCLUSION

The G-Branch endograft yielded high technical success with good early and midterm outcomes for the treatment of TAAA and PAAA. A large multicentre study is warranted.

Gore thoracoabdominal branched endoprosthesis: early results and impressions

The remarkable advances in technology and devices in the last two decades have made possible the endovascular repair of complex abdominal (cAAA) and thoracoabdominal (TAAA) aortic aneurysms with challenging anatomy. To date, despite the creation of multiple fenestrated/branched endografts intended to treat these difficult cases, in the USA, many of them remain available only under physician sponsored investigational device exemption (PSIDE) protocols in few institutions. The Gore Thoracoabdominal Branched Endoprosthesis (TAMBE; W.L. Gore & Associates, Flagstaff, AZ, USA) investigational device is a four-branched off-the-shelf (OTS) endograft that concluded an early feasibility study in 2016 and is currently finalizing a pivotal trial in pursuit of approval from the Food and Drug Administration. This article discusses the TAMBE early feasibility multicenter study results, the most relevant features of this device, its anatomical feasibility, and the impressions about this endograft as an OTS option for the treatment of CAAA and TAAA.

Suitability of current off-the-shelf devices for endovascular TAAA repair: a systematic review

INTRODUCTION

The aim of the present study is to perform a systematic review of published papers regarding the suitability of the current off-the-shelf (OTS) devices for endovascular thoracoabdominal aortic aneurysm (TAAA) repair.

EVIDENCE ACQUISITION

A systematic review of the MEDLINE database via PubMed was performed in March 2023. All studies reporting the outcomes of the three currently available OTS stent-grafts: the Zenith t-Branch (Cook Medical, Bloomington, IN, USA), the Gore Excluder thoracoabdominal branch endoprosthesis (TAMBE; W.L. Gore & Associates, Flagstaff, AZ, USA) and the E-nside Multibranch Stent-Graft System (Artivion, Kennesaw, GA, USA), were retrieved and further analyzed. The main endpoints were technical success, reintervention rate, and primary branch patency. Theoretical feasibility studies of these OTS devices were also included and separately analyzed.

EVIDENCE SYNTHESIS

A total of 19 studies were published between 2014 and 2023. Thirteen clinical studies and six theoretical feasibility studies were included. Eleven studies reported the clinical outcomes of the t-Branch stent-graft, one detailed the observational results of the use of the E-nside endoprosthesis, and one described the TAMBE stent-graft results. The following data primarily involve the t-Branch device outcomes. A total of 1131 patients that underwent aneurysm repair using an OTS stent-graft were identified. Among those, 1002, 116 and 13 patients received a t-Branch, E-nside, and TAMBE stent-grafts, respectively. A total of 767 (67.8%) were men, with a mean age of 71.6±7.4 years old, and a mean Body Mass Index (BMI) of 26.3±3.8 kg/m2. Technical success ranged from 64% to 100%. A total of 4172 target visceral vessels (TVV) were planned for bridging, with a success rate ranging from 92 to 100%. The total of early and late reinterventions reported were 64 and 48, respectively, mainly due to endoleaks and visceral branch occlusions. Among the theoretical feasibility studies, six described the feasibility of the t-Branch device in a total of 661 patients, two described the E-nside and the TAMBE devices feasibility comprising 351 patients for each stent-graft. The overall feasibility of the t-Branch device varied from 39% to 88%, the E-nside from 43% to 75%, and the TAMBE stent-graft ranged from 33% to 94%.

CONCLUSIONS

This systematic review demonstrated a good suitability for the use of OTS endografts for the treatment of TAAA.

Urgent and emergent repair of complex aortic aneurysms using an off-the-shelf branched device

Introduction

Endovascular repair using off-the-shelf endografts is a viable solution in patients with ruptured or symptomatic complex aortic aneurysms. This analysis aimed to present the peri-operative and follow-up outcomes in urgent and emergent cases managed with the t-Branch multibranched thoracoabdominal endograft.

Methods

Prospectively collected data from all consecutive urgent and emergent cases managed in two aortic centers between January 1st, 2014, to November 30th, 2022, using the t-Branch device (Cook Medical Inc., Bjaeverskov, Denmark) were analyzed. Patients presenting with ruptured aortic complex aneurysms were characterized as emergent and patients with aneurysms >90 mm of diameter, or symptomatic aneurysms were characterized as urgent. Technical success, 30-day mortality, major adverse events (MAE) and spinal cord ischemia (SCI) rates were assessed.

Results

225 patients (36.5% females, 72.5 ± 2.8 years) were included; 73.0% were urgent. The mean aneurysm diameter was 109 ± 3.9 mm and 44.4% were type I-III TAAAs. Females (p = .03), para-renal aneurysms (p = .02) and ASA score IV (p < .001) were more common in emergent cases. Technical success was 97.8%. Thirty-day mortality and MAE rates were 17.8% and 30.6%, respectively. SCI rate was 14.7%, (4.8% paraplegia rate) with 22.2% of patients receiving prophylactic cerebrospinal drainage. Thirty-day mortality (13.3% vs. 26.7%, p = .04) and MAE (26.0% vs. 43.0%, p = .02) were more common among emergent cases while technical success (97.6% vs. 98.3%, p = .9), and SCI (13.3% vs. 18.3%, p = .4) were similar. Survival at 12-months was 83.5% (SE 5.9%) for the urgent and 77.1% (SE 8.2%) for the emergent group (log rank, p = 0.96).

Conclusion

T-Branch represents an effective and safe solution for the management of urgent and emergent cases with complex aortic aneurysms, with high technical success, promising early mortality and SCI rates.

Effect of bridging stent graft selection for directional branches on target artery outcomes of fenestrated-branched endovascular aortic repair in the United States Aortic Research Consortium

OBJECTIVE

The purpose of this study was to evaluate the effect of directional branches (DBs) bridging stent choice on target artery (TA) outcomes during fenestrated-branched endovascular repair of complex abdominal and thoracoabdominal aortic aneurysms.

METHODS

Patients enrolled in nine prospective physician-sponsored investigational device exemption studies in the United States between 2005 and 2020 were analyzed. All patients who had at least one TA incorporated by DB using either self-expandable (SESGs), balloon-expandable (BESGs), or hybrid stent graft combinations (HSGs). Endpoints were TA patency and freedom from TA endoleak, instability, and reintervention.

RESULTS

There were 800 patients with 2426 renal-mesenteric arteries incorporated by DBs. DB stent selection was SESGs in 1205 TAs (50%), BESGs in 1095 TAs (45%), and HSGs in 126 TAs (5%). SESGs were predominantly used in the first three quartiles of the study period, whereas BESGs comprised 75% of all stents between 2017 and 2020. The median follow-up was 15 months (interquartile range, 6-35 months). At 5 years, BESGs had significantly lower freedom from TA instability (78% ± 4% vs 88% ± 1% vs 96% ± 2%; log-rank P =.010), freedom from TA endoleaks (87% ± 3% vs 97% ± 1% vs 99% ± 1%; log-rank P < .001), and freedom from TA reintervention (83% ± 4% vs 95% ± 1% vs 99% ± 2%; log-rank P <.001) compared with SESGs or HSGs, respectively. For renal arteries, there was no difference in freedom from TA instability for BESGs, SESGs, or HSGs. However, freedom from TA endoleaks and reintervention were lower for renal arteries targeted by BESGs compared with DBs targeted by SESGs and HSGs (83% ± 6% vs 98% ± 1% vs 100%; log-rank P < .001; and 70% ± 10% vs 92% ± 1% vs 96% ± 4%; log-rank P = .022). For mesenteric arteries, DBs targeted by BESGs had lower freedom from TA instability, endoleak, and reintervention than SESGs or HSGs. In stent-specific analysis, iCAST BESGs had the lowest freedom from TA instability either for renal or mesenteric arteries, primarily due to higher rates of TA endoleaks. There was no difference in patency in any scenario. Independent predictors of TA instability were age (+1-year: hazard ratio [HR], 0.97; 95% confidence interval [CI], 0.94-0.99), stent diameter (+1 mm: HR, 0.67; 95% CI, 0.57-0.80), and BESG (HR, 1.8; 95% CI, 1.1-2.9).

CONCLUSIONS

DBs incorporated using BESGs had lower freedom from TA instability, TA endoleak, and TA reintervention compared with SESGs and HSGs. The patency of DBs was not affected by the type of stent construction. The observed performance disadvantage associated with BESGs appears to have largely been driven by iCAST usage.

Emergent endovascular treatment options for thoracoabdominal aortic aneurysm

For a long time, parallel grafting, physician-modified endografts, and, more recently, in situ fenestration were the only go-to endovascular options for ruptured thoracoabdominal aortic aneurysm, offered mixed results, and depended mainly on the operator's and center's experience. As custom-made devices have become an established endovascular treatment option for elective thoracoabdominal aortic aneurysm, they are not a viable option in the emergency setting, as endograft production can take up to 4 months. The development of off-the-shelf (OTS) multibranched devices with a standardized configuration has allowed the treatment of ruptured thoracoabdominal aortic aneurysm with emergent branched endovascular procedures. The Zenith t-Branch device (Cook Medical) was the first readily available graft outside the United States to receive the CE mark (in 2012) and is currently the most studied device for those indications. A new device, the E-nside thoracoabdominal branch endoprosthesis OTS multibranched endograft (Artivion), has been made commercially available, and the GORE EXCLUDER thoracoabdominal branch endoprosthesis OTS multibranched endograft (W. L. Gore and Associates) is expected to be released in 2023. Due to the lack of guidelines on ruptured thoracoabdominal aortic aneurysm, this review summarizes the available treatment options (ie, parallel grafts, physician-modified endografts, in situ fenestrations, and OTS multibranched devices), compares the indications and contraindications, and points out the evidence gaps that should be filled in the next decade.

Branched and Fenestrated Aortic Endovascular Grafts

Endovascular repair of abdominal and descending thoracic aortic aneurysms has become the standard of care due to improvements in morbidity and mortality compared to open surgical repair. Late durability, however, remains an issue because persistent endoleaks can lead to continued aneurysm expansion and eventual rupture, sometimes years following the original repair. Branched, fenestrated, and physician-modified endografts in the thoracic arch and thoracoabdominal aorta have extended the seal zone in order to mitigate the risks of proximal and distal endoleaks. This review summarizes the current state of branched, fenestrated, and physician-modified endografts used in complex aortic pathologies.

Single-Center Experience with the Femoral-to-Brachial Preloaded Delivery System for Fenestrated-Branched Endovascular Repair of Complex Aortic Aneurysms

PURPOSE

To assess technical aspects and outcomes of fenestrated-branched endovascular aortic repair (FB-EVAR) using a femoral-to-brachial (FTB) preloaded delivery system (PDS) with two separate configurations.

METHODS

Clinical data of all consecutive patients enrolled in a prospective study to evaluate FB-EVAR for complex abdominal and thoracoabdominal aortic aneurysms (CAAAs & TAAA) between 2013 and 2020 were reviewed. Patients treated with FTB-PDS were included. The two configurations included 4 trans-brachial preloaded wires (4BR) or 2 trans-brachial and 2 transfemoral preloaded wires (2BR-2FE). Outcome measures included technical success, procedural metrics, 30-day or in-hospital mortality, major adverse events (MAEs), and target-vessel outcomes.

RESULTS

There were 115 patients with a mean age of 73.8 ± 8 years, treated with FTB-PDS. Of these, 62 patients (54%) had 4BR and 53 patients (46%) had 2BR-2FE FTB-PDS. There were 106 TAAA (92%) and 9 CAAAs (8%). Technical success, defined as successful implantation of the stent-graft and all intended target-vessel stents without type I or III endoleak, was 97%, with no differences in total operating time, endovascular time, and radiation dose between groups. There were 3 deaths (3%) at 30 days. MAEs were noticed in 21 patients (18%) with no difference between groups, including new-onset dialysis (2% vs. 4%, P = 0.59), and paraplegia (7% vs. 11%, P = 0.51), for 4BR and 2BR-2FE, respectively. Patient survival and freedom from aortic-related mortality at 2-years were 79 ± 5% and 97 ± 1.7%, respectively, with no difference between groups.

CONCLUSION

The use of FTB-PDS for FB-EVAR is safe with high technical success and a reasonable rate of MAEs. Each configuration provides specific benefits based on patient anatomy, while having similar procedural metrics and clinical outcomes.

Thoracoabdominal Aortic Disease and Repair: JACC Focus Seminar, Part 3

Thoracoabdominal aortic disease is a rare but life-threatening condition that requires expert multidisciplinary collaborative management. Intervention is indicated in patients with symptomatic aneurysms or when an aneurysm reaches a certain threshold of diameter or rate of expansion. The strategies for spinal cord and end-organ protection have evolved over several decades, resulting in improved outcomes after repair. Open repair, although invasive, provides definitive and durable repair. Endovascular approaches are rapidly evolving, and the results with fenestrated and branched endografts are promising. Both open repair and endovascular repair require highly specialized expertise, and outcomes are best when repair is undertaken in an elective setting by a dedicated team. Patients with degenerative thoracoabdominal aortic aneurysms and chronic dissections should be followed up closely and referred for elective repair when indicated.

Protocol for GUo's renovisceral Artery reconstruction-1: a prospective, multicentre, single-arm clinical trial to evaluate the safety and efficacy of a multibRANched sTEnt graft systEm for thoracoabdominal aortic aneurysm (GUARANTEE study)

INTRODUCTION

The multibranched off-the-shelf stent graft is a promising treatment option for thoracoabdominal aortic aneurysm (TAAA). A commercially available, multibranched, off-the-shelf endograft called the t-Branch stent graft has demonstrated favourable midterm outcomes. Another two investigational off-the-shelf endografts, the GORE EXCLUDER Thoracoabdominal Branch Endoprosthesis and E-nside multibranch stent graft system, are still being developed. However, these three endografts have an unsatisfactory anatomic feasibility rate in patients with TAAA. Based on the concept of Guo's renovisceral artery reconstruction-1, a novel, multibranched, off-the-shelf endograft with different configurations has been developed.

METHODS AND ANALYSIS

This prospective, multicentre, single-arm, cohort study will enrol 73 patients with TAAA. Preoperative and postoperative clinical data, as well as CT angiography images at each follow-up timepoint, will be analysed to evaluate the safety and efficacy of this novel, multibranched, off-the-shelf endograft for the treatment of TAAA. The primary safety end point is the major adverse event rate within 30 days after index endovascular aortic repair, including all-cause death, hepatic failure, bowel necrosis, renal failure, stroke, permanent paraplegia, cardiac infarction and respiratory failure. The primary efficacy end point is the successful treatment rate within 12 months after procedure, which is a composite of immediate technical success and no secondary surgical intervention related to TAAA within 12 months after the procedure.

ETHICS AND DISSEMINATION

The protocol has been reviewed and approved by the ethics committee of Chinese PLA General Hospital (reference number: 2021-NO.-007) and each participating hospital. The findings of this study will be disseminated through conference presentations, peer-reviewed journal publications and social media.

TRIAL REGISTRATION NUMBER

NCT05054985.

Meta-analysis of Comparative Studies Between Self- and Balloon-Expandable Bridging Stent Grafts in Branched Endovascular Aneurysm Repair

PURPOSE

Currently there is no robust evidence which type of bridging stent graft provides better outcomes after branched endovascular aortic repair (BEVAR). Self-expanding (SESG) and balloon-expandable (BESG) stent grafts are both commonly used to connect branches to their respective target vessels (TV). The aim of the current review was to evaluate the impact of the type of bridging stent grafts on TV outcomes during the mid-term follow-up after BEVAR.

MATERIALS AND METHODS

The study protocol was registered to the PROSPERO (CRD42021274766). A search of the English literature was conducted, using PubMed and EMBASE databases via Ovid and Cochrane database via CENTRAL, from inception to June 30, 2021, using the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. Only comparative studies on BEVAR reporting TV outcomes related to BESG vs SESG were considered eligible. Individual studies were assessed for risk of bias using the Newcastle Ottawa Scale. The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach was used to evaluate the quality of evidence. The primary outcomes were primary patency, freedom from endoleak, TV instability, and re-intervention between BESG and SESG, used as bridging stents in branches. The outcomes were summarized as odds ratio along with their 95% confidence intervals (CI), through a paired meta-analysis.

RESULTS

Five out of 609 articles published from 2016 to 2020 were included in the analysis. In total, 1406 TV were revascularized, 547 (38.9 %) with BESGs and 859 with SESGs. The overall pooled primary patency (odds ratio [OR], 0.40; 95% confidence interval [CI], 0.29-1.09; p=.256, I²=4.24%) and freedom from branch-related endoleak (OR, 0.65; 95% CI, 0.17-1.48; p<.122, I²=0.18%) did not differ between the stent types during the available follow-up (17 months, range = 12-35 months). In 4 studies (619 TV), SESG required fewer secondary interventions (OR, 1.04; 95% CI, 0.23-1.83; p=.009, I²=0%) and TV instability rate was lower (OR, 0.99; 95% CI, 0.33-1.65; p=.003, I²=0%) compared with BESG during the available follow-up.

CONCLUSION

BESG and SESG seem to perform similarly in terms of primary patency and branch-related endoleak during the mid-term follow-up. Current data from retrospective studies suggest that overall TV instability and re-intervention rates are favorable for SESG as bridging stent grafts in BEVAR.

Endovascular treatment of thoracoabdominal aortic aneurysms

Endovascular repair of thoracoabdominal aneurysms using fenestrated and/or branched stent grafts is technically feasible and efficacious but carries a steep learning curve. This innovative surgical approach is associated with less perioperative morbidity than traditional open repair and its early and mid-term outcomes are very favorable. Spinal cord ischemia remains a devastating complication after these procedures, hence the importance of various neuroprotective strategies. Widespread applicability remains limited in the United States, as no custom-made or off-the-shelf endografts are commercially available. Access to these devices remains limited to physician-sponsored or industry-sponsored clinical trials, but results from the Cook p-Branch and Gore Thoracoabdominal Branch Endoprosthesis trials are on the horizon.

Developing a morphomics framework to optimize implant site-specific design parameters for islet macroencapsulation devices

Delivering a clinically impactful cell number is a major design challenge for cell macroencapsulation devices for Type 1 diabetes. It is important to understand the transplant site anatomy to design a device that is practical and that can achieve a sufficient cell dose. We identify the posterior rectus sheath plane as a potential implant site as it is easily accessible, can facilitate longitudinal monitoring of transplants, and can provide nutritive support for cell survival. We have investigated this space using morphomics across a representative patient cohort (642 participants) and have analysed the data in terms of gender, age and BMI. We used a shape optimization process to maximize the volume and identified that elliptical devices achieve a clinically impactful cell dose while meeting device manufacture and delivery requirements. This morphomics framework has the potential to significantly influence the design of future macroencapsulation devices to better suit the needs of patients.

Comparison of anatomic feasibility of three different multibranched off-the-shelf stent-grafts designed for thoracoabdominal aortic aneurysms

OBJECTIVE

We compared the theoretical anatomic feasibility of endovascular treatment of thoracoabdominal aortic aneurysms (TAAAs) with three off-the-shelf multibranched stent-grafts: t-Branch (Zenith t-Branch; Cook Medical, Bloomington, Ind), Gore Excluder thoracoabdominal branch endoprosthesis (TAMBE; W. L. Gore & Associates, Flagstaff, Ariz), and E-nside (E-nside multibranch stent graft system; Jotec GmbH, Hechingen, Germany).

METHODS

Computed tomography scans of patients with degenerative TAAAs treated from 2007 to 2019 were reviewed, and the anatomic feasibility of the multibranched stent-grafts was assessed according to the manufacturer's instructions for use. The anatomic factors determining the overall feasibility were divided into access feasibility, aortic feasibility, and visceral vessel feasibility.

RESULTS

Degenerative TAAAs in 268 patients were analyzed. The overall feasibility did not differ significantly (TAMBE, 33%; t-Branch, 39%; E-nside, 43%; P = .271). Access, aortic, and visceral vessel feasibility alone excluded 18% to 22%, 35% to 49% and 21% to 26% of the patients respectively. The only significant difference between the devices was in aortic feasibility (P = .005), which was more frequently limited by the proximal aortic neck diameter in the TAMBE cohort and the inner visceral aortic diameter in the t-Branch cohort. The overall treatment feasibility using any of the three devices would have been 58%.

CONCLUSIONS

The new investigational off-the-shelf multibranched stent-grafts did not significantly improve the theoretical applicability in an extensive cohort of patients with TAAAs. Improvements are warranted to increase their overall feasibility.

Anatomical feasibility of a new off-the-shelf inner branch stent graft (E-nside) for endovascular treatment of thoraco-abdominal aneurysms

OBJECTIVES

METHODS

Preoperative computed tomography scans of patients with atherosclerotic TAAA treated between 2007 and 2019 were reviewed, and the anatomical feasibility of the E-nside graft was verified by a retrospective study (clinicaltrials.gov: NCT03959670) based on the investigational manufacturer instructions for use. The anatomical factors determining overall feasibility were divided into vascular access (AC) feasibility, aortic (AO) feasibility and visceral vessels (VV) feasibility.

RESULTS

Two hundred sixty-eight patients with thoraco-abdominal aneurysms were analysed: the overall treatment feasibility was 43%. AC feasibility was 78%, AO feasibility 60% and VV feasibility 79%. An iliac diameter &lt;8.5 mm excluded 21% of the patients. Aortic feasibility was limited by infrarenal aortic diameter (16%) and size of aortic lumen at the level of visceral vessels (14%). Visceral vessels feasibility was mainly limited by inadequate number (8%) or diameter (12%) of target vessels. Height and orientation of target vessels were adequate in 97% of the cases. Overall feasibility was negatively influenced by female gender (Odds ratio: 3.89; 95% confidence interval 2.03–7.44; P &lt; 0.001): the limiting factors in this subgroup being iliac diameter, infrarenal aortic diameter and visceral vessels diameter.

CONCLUSIONS

The E-nside off-the-shelf stent graft can be theoretically employed in almost half of the cases from an all-comers cohort of patients with TAAA. Improvement of device profile and creation of a dedicated infrarenal component are warranted to increase overall feasibility. Female gender significantly affects the overall feasibility.

Clinicaltrials.gov

NCT03959670.

Sex-Related Anatomical Feasibility Differences in Endovascular Repair of Thoracoabdominal Aortic Aneurysms With a Multibranched Stent-Graft

Purpose:

To evaluate the potential anatomical feasibility of using the off-the-shelf multibranched Zenith t-Branch for the treatment of thoracoabdominal aortic aneurysms (TAAAs) in female patients.

Materials and Methods:

A total of 268 patients (median age 68 years; 69 women) with degenerative TAAA treated at a single institution by means of open or endovascular repair between 2007 and 2019 were retrospectively analyzed to determine the feasibility of using the Zenith t-Branch based on the manufacturer’s instructions for use. The factors determining overall anatomical feasibility were divided into vascular access, aortic anatomy, and visceral vessels. The results were stratified by sex and compared. A logistic regression model was constructed to determine any association between feasibility and clinical factors or potential confounding variables; results are expressed as the odds ratio (OR) with 95% confidence interval (CI).

Results:

The overall anatomical feasibility was 39% (22% women vs 45% men, p=0.001). The feasibility was negatively influenced by female sex (p<0.001) in multivariable analysis (OR 2.9, 95% CI 1.5 to 5.4, p=0.001). Vascular access feasibility was 82% (61% women vs 89% men, p<0.001). Aorta feasibility was 65% (52% women vs 69% men, p<0.001), and visceral vessel feasibility was 74% (78% women vs 73% men, p=0.260). An access diameter ≤8.5 mm excluded 17% of the patients (39% women vs 9% men, p<0.001). The aortic feasibility was limited by the infrarenal aortic diameter in 16% of patients (45% women vs 6% men, p<0.001) and the aortic lumen at the visceral vessels in 17% patients (19% women vs 17% men, p=0.741). The visceral vessel feasibility was mainly limited by inadequate numbers or diameters of target vessels. Location and orientation of the target vessels were adequate in 96% of patients.

Conclusion:

A little more than a third of an all-comers cohort of patients with degenerative TAAA could have been treated with on-label use of the Zenith t-Branch. However, only 22% of women could have been treated because of sex-related anatomical limitations. New generations of multibranched devices should address these differences.

Open vs. endovascular thoracoabdominal aortic aneurysm repair: tale of the tape

Open surgical repair persists as the gold-standard operation for thoracoabdominal aortic aneurysm; however, endovascular repair has become commonplace. Technical considerations in thoracoabdominal aortic aneurysm treatment are particularly complex, insofar as it involves critical branching arteries feeding the visceral organs. Newer, low-profile devices make total endovascular thoracoabdominal aortic aneurysm repair more feasible and, thus, appealing. For younger and low-risk patients, the choice between open and endovascular therapy remains controversial. Despite the advantages of a minimally invasive procedure, data suggest that endovascular aortic repair incurs a greater risk of spinal cord deficit, and the durability of endovascular aortic repair remains unclear. It is difficult to compare outcomes between endovascular and open thoracoabdominal aortic aneurysm repair, primarily because of the current investigational status of endovascular devices, the variety of approaches to endovascular repair, differing patient populations, lack of prospective randomized studies, and minimal medium- and long-tern follow-up data on endovascular repair. When deciding between open and endovascular approaches, one should consider which is more suitable for each patient. Older patients generally benefit from a less invasive approach. Open repair should be considered for young patients and those with heritable thoracic aortic disease. Infection and fistulae are best treated by open repair, although endovascular intervention as a lifesaving bridge to definitive repair has evolved to become a critical component of initial treatment. It is crucial to have technical expertise in both open and endovascular procedures to provide the best aortic repair for the patient. This may require dedicated aortic programs at tertiary institutions.