Total Endovascular Repair of Complex Thoracoabdominal/Abdominal Aortic Aneurysms with a Four-Branched Off-the-Shelf G-Branch™ Stent Graft

Systematic Review and Meta-analysis of Outcomes of the Advanta V12 or iCAST Bridging Stent Graft Used for Fenestrated and Branched Endovascular Aortic Repair

OBJECTIVE

Half of re-interventions after fenestrated and branched endovascular aortic repair (FB-EVAR) are target vessel related. Regarding bridging stent choice, existing data are controversial. This meta-analysis aimed to evaluate the performance of Advanta V12/iCAST as the bridging stent in FB-EVAR.

DATA SOURCES

The English medical literature was searched through MEDLINE, Embase (via Ovid), and Cochrane databases (end date 15 April 2024).

REVIEW METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines and PICO (Patient, Intervention, Comparison, Outcome) model were followed. A predefined protocol was registered to PROSPERO (CRD42024556603). Randomised controlled trials and observational studies (2010 - 2024) reporting on Advanta V12/iCAST related target vessel outcomes were eligible. Risk of bias was assessed using ROBINS-I, and evidence quality was assessed via Grading of Recommendations Assessment, Development and Evaluations (GRADE). Primary outcomes were freedom from instability, stenosis and or occlusion, types Ic and IIIc endoleak, and re-intervention of target vessels bridged with the Advanta V12/iCAST. Prevalence and regression meta-analysis were performed.

RESULTS

From 1 439 articles, ten retrospective studies (7 525 target vessels; 3 890 target vessels bridged with Advanta V12/iCAST) were included. According to ROBINS-I, no study was of high quality. Mean follow up was 24.3 (95% confidence interval [CI] 23.9 - 24.7) months. Freedom from instability, stenosis and or occlusion, and types Ic and IIIc endoleak were 94% (95% CI 91 - 96%; p < .010; I2 = 91%; GRADE certainty, very low), 97% (95% CI 96 - 98%; p =  .070, I2 = 44%; GRADE certainty, low), and 97% (95% CI 94 - 98%; p < .010; I2 = 81%; GRADE certainty, very low), respectively. Freedom from target vessel re-intervention was 95% (95% CI 92 - 97%; p < .010; I2 = 85%; GRADE certainty, very low). Four studies provided extractable data on Advanta V12/iCAST in fenestrations and four in branches. No difference was detected in freedom from instability (p = .47), stenosis and or occlusion (p = .36), and types Ic and IIIc endoleak (p = .90). Freedom from re-intervention was 93% (95% CI 87 - 96%; p < .010; I2 = 90%) in fenestrations and 95% (95% CI 91 - 97%; p = .060, I2 = 64%) in branches.

CONCLUSION

The Advanta V12/iCAST bridging stent showed high freedom from target vessel instability, stenosis and or occlusion, and endoleak. Freedom from re-intervention was 95%, being similarly high in fenestrations and branches.

Early Results of the Newly-Designed Flowdynamics Dense Mesh Stent for Residual Dissection After Proximal Repair of Stanford Type A or Type B Aortic Dissection: A Preliminary Single-Center Report From a Multicenter, Prospective, and Randomized Study

BACKGROUND

Negative remodeling of the distal aorta due to residual dissection significantly impacts the long-term outcomes of dissection patients after proximal repair of acute aortic dissection. Branched/fenestrated aortic stents are technically demanding, and studies of the first generation of multilayer flow modulators for tackling this clinical scenario are few and limited. The single-center results from a multicenter, prospective, and randomized controlled study aimed to verify the safety and effectiveness of a newly-designed flowdynamics dense mesh stent for treating residual dissection after proximal repair.

METHODS

Patients with nonchronic residual dissection involving visceral branches were prospectively enrolled in 3 centers (ChiCTR1900023638). Eligible patients were randomly assigned to the flowdynamics dense mesh stent (FDMS) group and control group. Follow-up visits were arranged at 1, 3, 6, and 12 months after recruitment. The primary endpoints were all-cause and aortic-related mortality. The secondary endpoints included visceral branch occlusion, reintervention, and severe adverse events. Morphological changes were analyzed to exhibit the therapeutic effect. Our center participated in the multicenter prospective randomized controlled trial, and the preliminary single-center experience was reported.

RESULTS

Thirty-six patients were enrolled in our center, and the baseline characteristics of the 2 groups were comparable. Thirty-four patients completed the 12 month follow-up. Freedom from all-cause and aortic-related death were 94.4% and 100%. All visceral branches remained patent in the FDMS group. Increased area of the true lumen (1.03±0.38 vs 0.48±0.63 cm2 at the plane below renal arteries, p=0.006; 1.27±0.80 vs 0.32±0.50 cm2 at the plane 5 cm below renal arteries, p<0.001) and decreased area of the false lumen at the plane below renal arteries (-1.03±0.84 vs -0.15±1.21 cm2, p=0.023) were observed in the FDMS group compared with those parameters in the control group. The FDMS group showed a significant increase in true lumen volume (p<0.001) and a significant decrease in false lumen volume (p=0.018).

CONCLUSIONS

This newly-designed FDMS for endovascular repair of residual dissection after the proximal repair is safe and effective at 12 months.

CLINICAL IMPACT

One-year results of the randomized controlled clinical trial indicated the short-term safety and promising effect of FDMS on treating non-chronic residual dissection after proximal repair. At the 12th-month follow-up, the true lumen expanded, the false lumen shrunk and all visceral arteries kept patent. As far as I'm concerned, this is the first randomized controlled study concerning utilizing multilayer flow mesh stent treating aortic dissection. Despite a preliminary single-center report, our results are supposed to provide high-quality evidence to guide clinical practice and fill the gap in the application of FDMS.

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.

Aortic hemodynamic and morphological analysis before and after repair of thoracoabdominal aortic aneurysm using a G-Branch endograft

Background and objective: The G-Branch endograft is a novel multibranched "off-the-shelf" device used to repair thoracoabdominal aortic aneurysms (TAAAs). This report describes the hemodynamic and morphological performance of the G-Branch endograft in a human patient with TAAA. Materials and methods: We retrospectively reviewed the computed tomography angiography scans and clinical data of a woman in whom TAAA was treated using a G-Branch endograft. Patient-specific three-dimensional models were reconstructed, and computational fluid dynamics and morphological and hemodynamic indicators were analyzed before and after implantation of the device. Results: From a morphological perspective, there was an increase in cross-sectional area in the G-Branch endograft and all bridging stent grafts over time. Blood flow was redistributed among the renovisceral arteries, with a decrease in flow rate in the celiac artery and an increase in the left renal artery. Laminar blood flow was smoother and more rapid after implantation of the G-Branch device and remained stable during follow-up. In the bridging stent grafts, flow recirculation zones were found in the bridging zones of the celiac artery and superior mesenteric artery as well as the distal sealing zones of both renal arteries. Furthermore, higher time-averaged wall shear stress and a lower oscillatory index and relative resident time were found in the G-Branch endograft and bridging stent grafts. Quantitative analysis showed obvious reduction in the surface area ratio of the elevated time-averaged wall shear stress area and surface area ratio of the relative resident time after G-branch implantation. Conclusion: The revascularization of branch vessels occurred following G-branch implantation, with improvements arising not only from morphological changes but also from hemodynamic alterations. The long-term performance of the G-Branch endograft needs further investigation and clinical validation.

Endovascular Repair for Abdominal Aortic Aneurysm in Mainland China: A Systematic Review and Meta-Analysis

BACKGROUND

The aim of this study was to evaluate the safety, applicability, and outcomes of the endovascular aneurysm repair (EVAR) technique for patients in mainland China with abdominal aortic aneurysm (AAA) by performing a systematic review.

METHODS

We conducted a systematic search using the PubMed, Embase, Chinese National Knowledge Infrastructure, and Chinese Biomedical databases to identify Chinese studies on the management of AAAs using the EVAR technique published in English between January 2000 and December 2020. Two independent observers selected studies for inclusion in the study, assessed the methodological quality of the included studies, and extracted the data. The included studies investigated the clinical outcomes and postprocedural complications of using EVAR techniques.

RESULTS

Sixteen studies reported a total of 3,024 AAA patients. The follow-up period ranged from 1 to 133 months. The mean follow-up time was 38.5 months, the mean age was 69.2 years, and the mean aneurysm diameter was 56.1 mm. The pooled technical success rate was 95% (95% confidence interval [CI]: 92-96%). The endoleak rate was 7% (95% CI: 6-8%). The rate of endoleak requiring reintervention was 3% (95% CI: 3-4%). The 30-day morbidity rate was 9% (95% CI: 6-14%). The 30-day mortality rate was 2% (95% CI: 1-3%). The follow-up mortality was 5% (95% CI: 3-8%).

CONCLUSIONS

The results of the study showed that using the EVAR technique for treating patients in mainland China with AAAs produced encouraging mid-term outcomes. Long-term outcomes should be examined in future research.