Endovascular repair of abdominal and thoracoabdominal aneurysms using chimneys and periscopes is associated with poor outcomes

Urgent endovascular repair of juxtarenal/pararenal aneurysm by off-the-shelf multibranched endograft

OBJECTIVE

To report outcomes of urgent juxtarenal/pararenal aneurysms (J/P-AAAs) managed by off-the-shelf multibranched thoracoabdominal endografts (Cook, T-branch).

METHODS

In this observational, multicenter, retrospective study, patients with J/P-AAAs treated by urgent endovascular repair by T-branch in 23 European aortic centers, from 2013 to 2023, were analyzed. Contained J/P-AAAs rupture, presence of related symptoms, and aneurysm diameter of >70 mm were considered as indication for urgent repair. Technical success (TS), spinal cord ischemia (SCI), and 30-day/hospital mortality were assessed as early outcomes. Survival, freedom from reinterventions, and target artery instability (TAI) were evaluated during follow-up.

RESULTS

Overall, 197 patients (J-AAAs, n = 64 [33%]; P-AAAs, n = 95 [48%]; previous failed endovascular aneurysm repair (EVAR), n = 38 [19%]) were analyzed. The mean age and aneurysm diameter was 75 ± 8 years and 76 ± 4 mm, respectively. The American Society of Anesthesiologists score was 3 and 4 in 118 (60%) and 79 (40%) patients. Rupture, symptoms, and diameter of >70 mm were present in 51 (26%), 110 (56%), and 53 (27%) patients, respectively. An adjunctive proximal thoracic endograft was used in 28 cases (14%). The mean aortic coverage between the upper portion of the endograft and the lowest renal artery was 154 ± 49 mm. Single-stage repair and cerebrospinal fluid drainage were reported in 144 (73%) and 53 (27%) cases, respectively. TS was achieved in 182 (92%) cases (rupture, 84% vs no rupture, 95%; P = .02). Failures consist of TA loss (11 [6%]: renal artery, 9; celiac trunk, 2), type I to III endoleaks (2 [1%]), and 24-h mortality (2 [1%]). Rupture was a risk factor for technical failure (P = .02; odds ratio [OR], 3.8; 95% confidence interval [CI], 1.1-12.1). Overall, 15 patients (8%) had persistent SCI (rupture, 14% vs no rupture, 5%) with 11 (6%) , of paraplegia (rupture, 10% vs no rupture, 5%; P = .001). Rupture (P = .04; OR, 3.1; 95% CI, 1.1-8.9) and adjunctive proximal thoracic endograft (P = .01; OR, 4.1; 95% CI, 1.3-12.9) were risk-factors for SCI. Twenty-two patients (11%) died within 30 days or during a prolonged hospitalization. Previous failed EVAR (P = .04; OR, 3.6; 95% CI, 1.1-12.3), paraplegia (P < .001; OR, 9.9; 95% CI, 1.6-62.2) and postoperative mesenteric complications (P = .03; OR, 10.4; 95% CI, 1.2-93.3), as well as cardiac (P = .03; OR, 8.2; 95% CI, 2.0-33.0) and respiratory (P < .001; OR, 10.1; 95% CI, 2.9-35.2) morbidities were associated with 30-day/hospital mortality. The mean follow-up was 19 ± 5 months. The estimated 3-year survival and freedom from reinterventions was 58% and 77%, respectively. TAI occurred in 27 patients (14%) (occlusion, 15; endoleak, 14) with an estimated 3-year freedom from TAI of 72%.

CONCLUSIONS

Urgent repair of J/P-AAAs by T-branch is feasible and effective with satisfactory TS and 30-day/hospital mortality in high-risk patients. However, extensive aortic coverage is necessary, leading to a non-negligible SCI rate, especially in case of aortic rupture or when adjunctive thoracic endografts are necessary. Previous failed EVAR and postoperative mesenteric complications, as well as cardiac and respiratory morbidities were associated with 30-day/hospital mortality and should be subjected to more research for the purposes of improving 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.

Outcomes of Staged Repairs of Complex Endovascular Repairs of Thoracoabdominal Aortic Aneurysms

BACKGROUND

Endovascular treatment allows for the staging of thoracoabdominal aortic aneurysm repairs (eTAAAs) in an effort to decrease the risk of spinal cord ischemia (SCI), but data are limited.

METHODS

We studied all eTAAAs in the Vascular Quality Initiative from 2014 to 2021. Inverse probability weighting was used to compare perioperative and long-term outcomes of staged and single-stage repairs. Thoracoabdominal life-altering events (TALEs) are the composite endpoint consisting of death/stroke/permanent SCI/permanent dialysis.

RESULTS

There were 3,258 total operations during the study period. In total, 841 cases (26%) were staged repairs, and 2,417 (74%) were completed in a single stage, but in the cohort of patients with extensive aneurysms, 44% were staged. Staging methods included thoracic endograft (78%), branch (23%), and iliac (5%). Staged repairs were more often employed by high-volume surgeons at high-volume centers; for larger, more extensive aneurysms, with higher rates of prior aortic surgery. After adjustment, staged repair and single-stage treatment were associated with similar odds of all perioperative outcomes and including mortality, TALE, acute kidney injury, stroke, dialysis, and SCI, as well as long-term survival. This was consistent in the subgroups of patients with extensive aneurysms undergoing elective procedures. Of note, first-stage thoracic endografts were associated with 2.6% mortality, 7.3% TALE, 1.5% dialysis, and 4.1% SCI, and 25% of patients did not undergo a second stage. First-stage procedures accounted for one-third of perioperative complications including half of the deaths in the staged cohort.

CONCLUSIONS

Staged eTAAA repairs were associated with similar perioperative and long-term complications to single-stage treatments. However, first stage procedures are associated with significant morbidity and mortality, and one-quarter of patients never complete their repairs. These data demonstrate the necessity of evaluating the outcomes of all patients planned for staged procedures, not only those who make it to the final stage. More data are needed as to the optimal method of spinal cord protection for these challenging aneurysms.

Computational study of fenestration and parallel grafts used in TEVAR of aortic arch aneurysms

To explore the differences between fenestration technique and parallel grafts technique of thoracic endovascular aortic repair, and evaluate the risk of complications after interventional treatment of aortic arch aneurysms. A three-dimensional aortic model was established from the follow-up imaging data of patient who reconstructed the superior arch vessel by the chimney technique, which was called the chimney model. Based on the chimney model, the geometric of the reconstructed vessel was modified by virtual surgery, and the normal model, fenestration model and periscope model were established. The blood flow waveforms measured by 2D phase contrast magnetic resonance imaging were processed as the boundary conditions of the ascending aorta inlet and the superior arch vessels outlets of the normal model. The pressure waveform of descending aorta was obtained using three-element Windkessel model, and specific pressure boundary conditions were imposed at reconstructed branches for the postoperative models. Through computational fluid dynamics simulations, the hemodynamic parameters of each model were obtained. The reconstructed vessel flow rate of the periscope model and the fenestration model are 33% and 50% of that of the normal model, respectively. The pressure difference between the inner and outer walls of the fenestration stent and periscope stent is 3.15 times and 7.56 times that of the chimney stent. The velocity in the fenestration stent and periscope stent is uneven. The high relative residence time is concentrated in the region around the branch stents, which is prone to thrombosis. The "gutter" part of the chimney model may become larger due to the effect of the stent-graft DF, increasing the risk of endoleak. For patients with incomplete circle of Willis, the periscope technique to reconstruct the supra-arch vessels may affect blood perfusion. It is recommended to use balloon-expandable stent for fenestration stent and periscope stent, and self-expanding stent for chimney stent. For patients with aortic arch aneurysms, the fenestration technique may be superior to the parallel grafts technique.

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.

Combining Endovascular Aneurysm Sealing with Chimney Grafts - 5 Year Follow-Up after 47 Procedures

BACKGROUND

To evaluate longer-term results of a cohort treated with primary chimney endovascular aneurysm sealing (ChEVAS) for complex abdominal aortic aneurysms or secondary ChEVAS after failed endovascular aneurysm repair/endovascular aneurysm sealing.

METHODS

A single-center study was conducted of 47 consecutive patients (mean age 72 ± 8 years, range 50-91; 38 men) treated with ChEVAS from February 2014 to November 2016 and followed through December 2021. The main outcome measures were all-cause mortality (ACM), aneurysm-related mortality, occurrence of secondary complications and conversion to open surgery. Data are presented as the median (interquartile range [IQR]) and absolute range.

RESULTS

35 patients received a primary ChEVAS (=group I) and 12 patients a secondary ChEVAS (=group II). Technical success was 97% (group I) and 92% (group II); 30-day mortality was 3% and 8%, respectively. The median proximal sealing zone length was 20.5 mm (IQR 16, 24; range 10-48) in group I and 26 mm (IQR 17.5, 30; range 8-45) in group II, respectively. During a median time of follow-up of 62 months (range 0-88), ACM amounted to 60% (group I) and 58% (group II); aneurysm mortality was 29% and 8%, respectively. An endoleak was seen in 57% (group I: 15 type Ia endoleaks, four isolated type Ib, and 1 endoleak type V) and 25% (group II: 1 endoleak type Ia, one type II, and 2 type V), aneurysm growth in 40% and 17%, migration in 40% and 17%, resulting in 20% and 25% conversions in group I and II, respectively. Overall a secondary intervention was performed in 51% (group I) and 25% (group II), respectively. The occurrence of complications did not significantly differ between the 2 groups. Neither the number of chimney grafts, nor the thrombus ratio significantly affected the occurrence of abovementioned complications.

CONCLUSIONS

While initially delivering a high technical success rate, ChEVAS fails to provide acceptable longer-term results both in primary and secondary ChEVAS, resulting in high rates of complications, secondary interventions and open conversions.

Fenestrated Physician-Modified Endografts for Preservation of Main and Accessory Renal Arteries in Juxtarenal Aortic Aneurysms

BACKGROUND

There is a paucity of reporting outcomes of complex aortic aneurysm treatment such as juxtarenal abdominal aortic aneurysms, where additional techniques to preserve renal artery perfusion are required.

METHODS

Retrospective analysis of consecutive patients who underwent emergent and elective aortic repair with fenestrated PMEGs between March 2019 and January 2023. Endpoints were technical success, reinterventions, secondary reinterventions and target vessel patency.

RESULTS

Forty-seven target vessels in 37 patients (23 male, median age 75 years) were targeted, of which 44 were renal arteries (RAs) with a mean diameter of 5.4 ± 1.0 mm. Thirteen were accessory RAs and six had a diameter ≤ 4 mm. Technical success rate was 87% overall; 97% for main and 62% for accessory RAs respectively. Target vessel patency and freedom from secondary reintervention was 100% and 97% at 30 days and 96% and 91% at one year, respectively. There was no 30-day mortality.

CONCLUSION

Fenestrated physician-modified endografts are safe and effective for the treatment of patients with juxtarenal abdominal aortic aneurysms when incorporating main renal arteries. Limited technical success may be expected when targeting accessory renal arteries, especially when small in diameter. Long-term follow-up is needed to confirm durability of PMEGs for renal artery preservation.

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.