Self-Radiopaque Markers Guiding Physician-Modified Fenestration (S-Fenestration) in Aortic Arch Endovascular Repair

Current techniques of repair of aortic arch pathologies and the role of the aortic team

The treatment of aortic arch pathologies is becoming progressively more complex and multidisciplinary. Despite progresses in open surgical techniques, the high rate of surgical morbidity and mortality, especially in frail and elderly patients, has led to the development of alternative treatment options to conventional open surgery such as hybrid and endovascular procedures. Our purpose is to summarize the advantages and disadvantages of the different approaches and investigate the role of a dedicated aortic team in the choice of the most appropriate treatment for each patient.

In Situ Fenestration and Carotid-Subclavian Bypass for Left Subclavian Artery Revascularization During Thoracic Endovascular Aortic Repair

PURPOSE

To evaluate the safety and feasibility of left subclavian artery (LSA) revascularization techniques during thoracic endovascular aortic repair (TEVAR)-the in situ needle fenestration (ISNF) technique and the carotid-subclavian bypass (CS-Bp)-for complicated aortic pathologies.

METHODS

A retrospective single-center observational study was conducted to identify all patients with thoracic aortic pathologies who underwent TEVAR with LSA revascularization using either CS-Bp or ISNFs from January 2014 to December 2020.

RESULTS

One hundred and twelve consecutive patients who received TEVAR with LSA revascularization were included. Among them, 69 received CS-Bp and 43 received ISNF (29 using the Futhrough adjustable puncture needles, 14 using the binding stent-graft puncture systems). Technical success, defined as achieving aortic arch pathology exclusion and LSA preservation, was attained in 99.1% patients. Early mortality was 0.9%. Major adverse events within 30 days, including one cerebral hemorrhage, one cervical incision hemorrhage, one stroke and two paraplegia, were exclusively observed in the CS-Bp group. Immediate type I, II and III endoleaks occurred in 0%, 4.7% and 2.3% in the ISNF group, respectively, compared to 0%, 2.9% and 0% in the CS-Bp group.One hundred and eight (97.2%) patients were available for follow-up at a median 50 (maiximum of 103) months, revealing a LSA patency rates of 99.1%. Six patients died during follow-ups-five in the CS-Bp group and one in the ISNF group. Cause of death include one aortic-related stent-graft infection, three non-related and two with unknow causes. The survival exhibited no significantly different between the ISNF (97.7%) and CS-Bp (89.9%) groups (p = 0.22).

CONCLUSIONS

Both CS-Bp and ISNF are feasible techniques for LSA reconstruction in TEVAR. ISNF, whether using Futhrough or BPS, seems to be competitive with CS-Bp.

Comparison of Chimney and Fenestrated Techniques for Supra-Aortic Branch Revascularization During Thoracic Endovascular Aortic Repair: A Systematic Review and Meta-Analysis

PURPOSE

To compare the technical and clinical outcomes of fenestrated thoracic endovascular aortic repair (F-TEVAR) and chimney thoracic endovascular aortic repair (CH-EVAR) of aortic disease.

METHODS

PubMed, Embase and Cochrane databases were systematically searched to identify studies on the management of thoracic aortic pathologies using chimney or fenestrated techniques published between 2000 and 2022. Individual studies provided at least one of the following essential outcomes: technical success, immediate and follow-up type I endoleak, 30-day and aorta-related mortality, cerebral events and supra-aortic branch patency.

RESULTS

24 chimney (1106 patients) and 21 fenestrated technique studies (1040 patients) were included. The scope of the study encompassed various thoracic aortic conditions, such as thoracic aortic dissection, thoracic aortic aneurysm, thoracic aortic ulcer, and other thoracic aortic diseases. Technical success was defined as the handling of the principal ailment affecting the aorta, devoid of any instances of complications. The technical success rates were higher in fenestrated group compared with chimney group (98.0% vs. 95.8% p < 0.001), and the rate of type I endoleak either immediately or during follow-up was higher in the chimney technique group (9.3% vs. 1.3% p < 0.001, 4.0% vs. 0.0% p < 0.001). The chimney technique group had higher 30-day mortality and aorta-related mortality than those in the fenestrated technique group (2.1% vs. 0.3% p < 0.001, 0.4% vs. 0.0% p < 0.001). Morbidity rates of cerebral events and supra-aortic branch patency were same in both groups (2.2% vs. 1.1% p = 0.116, 98.2% vs. 99.4% p = 0.094). The chimney technique group had longer operative time (110.0 min vs. 90.8 min p < 0.001). Two groups had same fluoroscopy time (34.0 min vs. 33.4 min p = 0.614).

CONCLUSIONS

The finding suggest that both the chimney and fenestrated techniques are efficacious in supra-aortic branch reconstruction. However, the fenestrated technique exhibits potential superiority as an interventional strategy, as it demonstrates a lower incidence of type 1 Endoleak, 30-day mortality, and aorta-related death following TEVAR.

Animal study on adjustable pre fenestration aortic stent graft

OBJECTIVES

To isolate aortic arch pathologies and keep the branches superior in arch patent, it always need physicians to do in-vivo fenestration or in-situ fenestration when performing the thoracic endovascular aortic repair (TEVAR). However, both of those fenestration techniques need structure modification of the stent-graft, which may affect their long-term stability. We designed an adjustable pre-fenestration aortic stent-graft to treat pathologies in this area and obtained a patent branch arteries. This study used this new designed stent-graft to perform fenestrated-TEVAR (f-TEVAR) in canine aorta. This study aims to identify its feasibility and safety through animal experiments, which might provide preliminary data for potential human implantation.

METHODS

A total of 8 Labrador Retrievers were underwent f-TEVAR by using the new devices. Digital subtraction angiography was performed before and after f-TEVAR to evaluate the success of the procedures. All the canines were divided into a 4-week group (feeding for 4 weeks after operation) and a 12-week group (feeding for 12 weeks after operation). Computed tomography angiography (CTA) were performed before euthanasia.

RESULTS

The success rate of operation was 100%. During the operation, there was no accident of major bleeding or failure to be released by fenestration. Adjustable fenestration worked well. No stent-graft migration was found in CTA at 4 weeks and 12 weeks after the operation. All branch arteries kept by the adjustable fenestration were patent.

CONCLUSIONS

The result of feasibility and safety of the new designed adjustable pre-fenestration aortic stent-graft in f-TEVAR of canine is acceptable. This study provides a reference for further optimization of this stent and human f-TEVAR implantation involving aortic arch lesions.

Research and clinical translation of trilayer stent-graft of expanded polytetrafluoroethylene for interventional treatment of aortic dissection

The aortic dissection (AD) is a life-threatening disease. The transcatheter endovascular aortic repair (EVAR) affords a minimally invasive technique to save lives of these critical patients, and an appropriate stent-graft gets to be the key medical device during an EVAR procedure. Herein, we report a trilayer stent-graft and corresponding delivery system used for the treatment of the AD disease. The stent-graft is made of nitinol stents with an asymmetric Z-wave design and two expanded polytetrafluoroethylene (ePTFE) membranes. Each of inner and outer surfaces of the stent-graft was covered by an ePTFE membrane, and the two membranes were then sintered together. The biological studies of the sintered ePTFE membranes indicated that the stent-graft had excellent cytocompatibility and hemocompatibility in vitro. Both the stent-graft and the delivery system exhibited satisfactory mechanical properties and operability. The safety and efficacy of this stent-graft and the corresponding delivery system were demonstrated in vivo. In 9 canine experiments, the blood vessels of the animals implanted with the stent-grafts were of good patency, and there were no thrombus and obvious stenosis by angiography after implantation for 6 months. Furthermore, all of the 9 clinical cases experienced successful implantation using the stent-graft and its post-release delivery system, and the one-year follow-ups indicated the preliminary safety and efficacy of the trilayer stent-graft with an asymmetric Z-wave design for interventional treatment.

First-in-Human Implantation of Gutter-Free Design Stent-Graft in in situ Fenestration TEVAR for Aortic Arch Pathology

Purpose

To report the technology and preliminary result of gutter-free design stent-grafted in in situ fenestration thoracic endovascular aortic repair (TEVAR).

Description

The gutter-free stent-graft has a nickel-titanium self-expanding skeleton, double polytetrafluoroethylene coating, and an outer-skirt fabric structure (named C-skirt endograft). The outer skirt fabric prevents endoleak from the gutter around the stent graft fenestration. Further, the skirt structure right under the fenestration in the aortic stent graft can function as a fixation of the side-branch artery endograft. These designs have the following advantages, such as: 1) prevention of endoleak; and 2) fixation tightly between the branch and aorta endograft pieces.

Evaluation

A patient who was diagnosed with an aortic arch aneurysm, combined with localized dissection, has successfully implanted the aortic stent graft and C-skirt endograft for the left subclavian artery. The 6-month follow-up result of the C-skirt in situ fenestration TEVAR is satisfactory without obvious endoleak.

Conclusions

The new gutter-free C-skirt stent graft is being safely and effectively used for aortic arch TEVAR. Long-term evaluation of safety, effectivity, and durability needs to be proven by future multi-center studies.