Retrograde Fenestration of Endoluminal Grafts from Target Vessels: Feasibility, Technique, and Potential Usage

Early Clinical Outcomes of Retrograde In-Situ Branched Stent Grafting for Complex Aortic Arch Aneurysms

OBJECTIVE

To evaluate the early outcomes of retrograde in-situ branched stent grafting (RIBS) using the gutter balloon technique for complex aortic arch aneurysms (CAAs).

METHODS

The RIBS technique is an in-situ needle fenestration procedure during thoracic endovascular aortic repair (TEVAR) with the reconstruction of cervical branches. The Double-RIBS (D-RIBS) for the reconstruction of the left common carotid artery and the brachiocephalic artery using the gutter balloon technique was performed in 30 high-risk patients. We describe the early clinical results of the D-RIBS technique for CAAs. Primary endpoints were technical success and 30-day mortality. Secondary endpoints were postoperative complications, rates of endoleaks, overall survival, aneurysm-related death, and re-interventions.

RESULTS

The mean age was 77.1±6.6 years and the mean maximum minor-axis aneurysmal diameter was 65.9±8.9 mm. Twenty six patients underwent D-RIBS for elective arch aortic aneurysm and four patients were for reintervention after Zone 2 TEVAR failure. Stent graft puncture was performed 60 times from the common carotid arteries and technical success was achieved in all cases (100%). Postoperative complications included cerebral infarction in 2 patients (6.7%), recurrent nerve palsy in one patient (3.3%). The 30-day mortality was 0%. During the median follow-up period of 14 months (6-56), overall survival at 12 months was 92.3% without any aneurysm-related death. Type 1b and type 2 endoleaks were observed in one each and no reintervention was encountered.

CONCLUSION

Early clinical outcomes of the D-RIBS for high-risk patients with CAAs are acceptable. The gutter balloon method enables safe and reliable fenestration. Further studies and dedicated devices are warranted.

Caudally directed in situ fenestrated endografting for emergent thoracoabdominal aortic aneurysm repair

We previously described a transfemoral antegrade in situ laser fenestration technique (in situ fenestrated endovascular abdominal aortic aneurysm repair) for ruptured thoracoabdominal aortic aneurysms. In the present report, we have described an alternative technique of caudally directed in situ fenestrated endografts using upper extremity access for branch vessel incorporation. This technique involves partial deployment of the aortic stent graft in the thoracic aorta to achieve proximal control, followed by sequential branch incorporation using a laser probe through a steerable sheath, from the upper extremity access. The advantages of the technique include rapid proximal aortic control before branch incorporation without target vessel prestenting and separation of in situ fenestration from the target branch vessel origin, facilitating cannulation of angulated branch vessels.

Evaluation for the safety and effectiveness of the in situ fenestration system in TEVAR for aortic arch pathologies: protocol for a prospective, multicentre and single-arm study

INTRODUCTION

Thoracic endovascular aortic repair (TEVAR) has gradually become the mainstream therapy for aortic arch pathologies (AAP). Our centre developed the in situ fenestration (ISF) system according to years of clinical experience and technological innovation. This study aims to evaluate the safety and effectiveness of the innovative, self-developed ISF system in TEVAR for AAP.

METHODS AND ANALYSIS

The study is a prospective, multicentre and single-arm study. Patients diagnosed with AAPs in five centres on 1 January 2021 will be recruited and general TEVAR with ISF system will be performed. Clinical information and CT angiography images will be collected and recorded. Patients will be followed up for 5 years. Safety and efficacy endpoints are planned to be reported to evaluate this self-developed ISF system.

ETHICS AND DISSEMINATION

The study is a registry. We have registered the study on the Chinese Clinical Trial Registry website (http://www.chictr.org.cn/). This study has been approved by the Ethics Committee of Zhongshan Hospital Fudan University (B2020-371) and individual consents will be signed at the time of enrolment. We anticipate that this self-developed ISF system will result in favourable social and economic benefits. Findings will be disseminated in peer-reviewed journals to provide reference for future clinical practice.

TRIAL REGISTRATION NUMBER

ChiCTR1900026696.

Antegrade in situ fenestrated endovascular repair of a ruptured thoracoabdominal aortic aneurysm

We describe a technique for antegrade in situ laser fenestration that has several advantages in the setting of ruptured thoracoabdominal aortic aneurysms. This technique involves rapid aneurysm sealing by deployment of aortic stent graft, followed by sequential incorporation of branch vessels using a laser probe through steerable sheath. The advantages of this technique include (1) rapid seal of the ruptured aneurysm, (2) preservation of the visceral and renal branch perfusion, (3) use of an off-the-shelf device, and (4) the ability to be performed without general anesthesia.

Novel EM Guided Endovascular Instrumentation for In Situ Endograft Fenestration

Objective: This work aims at providing novel endovascular instrumentation to overcome current technical limitations of in situ endograft fenestration including challenges in targeting the fenestration site under fluoroscopic control and supplying mechanical support during endograft perforation. Technology: Novel electromagnetically trackable instruments were developed to facilitate the navigation of the fenestration device and its stabilization at the target site. In vitro trials were performed to preliminary evaluate the proposed instrumentation for the antegrade in situ fenestration of an aortic endograft, using a laser guidewire designed ad hoc and the sharp end of a commercial endovascular guidewire. Results: In situ fenestration was successfully performed in 22 trials. A total of two laser tools were employed since an over bending of laser guidewire tip, due to its manufacturing, caused the damage of the sensor in the first device used. Conclusions: Preliminary in vitro trials demonstrate the feasibility of the proposed instrumentation which could widespread the procedure for in situ fenestration. The results obtained should be validated performing animal studies. Clinical Impact: The proposed instrumentation has the potential to expand indications for standard endovascular aneurysm repair to cases of acute syndromes.

In situ diode laser fenestration: An ex-vivo evaluation of irradiation effects on human aortic tissue

The in situ laser fenestration is an interesting option for the endovascular treatment of short-necked aneurysms with an intraoperative modification of a standard endograft. According to literature evidence, diode laser emitting in the near-infrared wavelength (810 nm) can be successfully used to fenestrate the endograft fabric. This paper describes a three-dimensional navigation system for the accurate targeting of the fenestration site, then reports results of an ex vivo study to assess whether the laser operative conditions, which ensure the fabric fenestration, are harmless for the biological tissue surrounding the endoprosthesis. Two hundred twenty-five samples of human aorta, including healthy specimens and abdominal aortic aneurysm samples, were irradiated ex vivo using a 810 nm diode laser. Energy and pulse duration were varied. Irradiated tissues were fixed in formaldehyde, sectioned and subjected to histological examination. Only 7.5% of the irradiated samples exhibited a thermal damage, which was always confined to the contact point between the laser fiber tip and the aortic wall. These experiments suggest that the diode laser can be safely used for the proposed surgical application.

Multicenter Analysis of Endovascular Aortic Arch In Situ Stent-Graft Fenestrations for Aortic Arch Pathologies

BACKGROUND

In situ fenestration of aortic stent grafts for treatment of aortic arch aneurysms is a new option for endovascular aortic arch repair. So far, only few reports have shown perioperative and short-term results of in situ fenestrations for aortic arch diseases. We present the multicenter experience with the aortic arch in situ fenestration technique documented in the AARCHIF registry for treatment of aortic arch aneurysms or localized type A aortic dissections and analyzed perioperative outcome and midterm follow-up.

METHODS

Patients with aortic arch pathologies treated by aortic arch in situ fenestration with proximal stent graft landing in aortic arch Ishimura zones 0 and 1 were included in the registry. Stent-graft in situ fenestrations were created using needles or radiofrequency or laser catheters and completed by implantation of covered connecting stent grafts. Single in situ fenestrations for the left subclavian artery (LSA) were excluded.

RESULTS

Between 06/2009 and 03/2017, twenty-five patients were treated by in situ stent-graft fenestrations for aortic arch pathologies at 9 institutions in 7 different countries, 3 of them as bailout procedures for stent-graft malplacement. In situ fenestrations were performed for the brachiocephalic trunk (n = 20), the left common carotid artery (n = 21) and the LSA (n = 9). Technical success for intended in situ fenestrations was 94.0% (47/50), with additional supraaortic bypass procedures performed in 14 patients. Perioperative mortality occurred in 1 (4.0%) patient, treated as a bailout procedure and 3 (12.0%) perioperative strokes were observed. One proximal aortic stent-graft nonalignment and 4 type III endoleaks, 2 early and 2 late, required reeintervention. During follow-up (1-118 months), the diameter of aortic arch aneurysms decreased from 61.5 ± 4.1 mm to 48.4 ± 3.2 mm (P = 0.02) and, so far, 6 patients died from diseases unrelated to their aortic arch pathologies with a mean survival time of 79.5 months and 3 endovascular reinterventions for distal aortic expansion were performed. Cerebrovascular event (n = 4) was the most relevant prognostic factor for mortality during midterm follow-up (P = 0.003).

CONCLUSIONS

The aortic arch in situ fenestration technique for endovascular aortic arch repair seems to be valuable treatment option for selected patients, although initial consideration of other treatment options is mandatory. Data about long-term durability are required.

A New Adjustable Puncture Device for In Situ Fenestration During Thoracic Endovascular Aortic Repair

Purpose: To describe a new adjustable puncture system for in situ fenestration in thoracic endovascular aortic repair (TEVAR). Technique: An adjustable puncture needle for use in conjunction with a steerable 8-F, 55-cm Fustar sheath is demonstrated in a 65-year-old man with acute complicated type B dissection involving the left subclavian artery (LSA). The puncture device features an inflatable balloon at the tip, a central lumen for 0.018-inch guidewires, and a 3-level puncture depth. After thoracic stent-graft deployment at zone 2, the needle/sheath combination was delivered from a left brachial artery access. The needle was adjusted perpendicular to the fabric of the stent-graft with the assistance of the steerable sheath. The balloon at the tip was inflated to center the needle, and the puncture depth was selected on the puncture needle system. Holding the sheath and puncture needle together, a hole was created in the graft fabric. The aperture was sequentially dilated to accommodate the mating stent selected to maintain perfusion to the LSA. This new device has been successfully applied in 6 patients treated with TEVAR for different arch pathologies. Conclusion: This new puncture device could assist in situ fenestration and improve the technical success rate.

A Comprehensive Review of In Situ Fenestration of Aortic Endografts

OBJECTIVE

Despite technical advances of fenestrated and branched endografts, endovascular exclusion of aneurysms involving renal, visceral, and/or supra-aortic branches remains a challenge. In situ fenestration (ISF) of standard endografts represents another endovascular means to maintain perfusion to such branches. This study aimed to review current indications, technical descriptions, and results of ISF.

METHOD

A review of the English language literature was performed in Medline databases, Cochrane Database, Web of Science, and Scopus using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Sixty-seven relevant papers were selected. Thirty-three papers were excluded, leaving 34 articles as the basis of the present review.

RESULTS

Most experimental papers evaluated ISF feasibility and assessed the consequences of ISF on graft fabric. Regarding clinical papers, 73 ISF procedures have been attempted in 58 patients, including 26 (45%) emergent and three (5%) bailout cases. Sixty-five (89%) ISF were located at the level of the arch, and eight (11%) in the abdominal aorta. Graft perforation was performed by physical, mechanical, or unspecified means in 33 (45%), 38 (52%), and two vessels (3%), respectively. ISF was technically successful in 68/73 (93%) arteries. At 30 days, two (3.4%) patients died in the setting of an aorto-bronchial fistula and an aorto-oesophageal fistula, respectively. No post-operative death, major complication, or endoleak was described as secondary to the ISF procedure. With follow-up between 0 and 72 months, four (6.9%) late deaths were noted, unrelated to the aorta. One (1.7%) LSA stent was stenosed without symptoms.

CONCLUSIONS

Although there may be publication bias, multiple techniques were described to perform ISF with satisfactory short-term results. Long-term data remain scarce. Aortic endograft ISF is an off-label procedure that should not be used outside emergent bailout techniques or investigational studies. A comparison with alternative techniques of preserving aortic side branches is needed.

In Vivo Antegrade Fenestration of Abdominal Aortic Stent-Grafts

Purpose:

To examine in a canine model the feasibility of antegrade fenestration of abdominal aortic stent-grafts to preserve the patency of the renal arteries.

Methods:

Two large dogs underwent antegrade fenestration of stent-grafts in the perirenal aorta. Before fenestration, bare stents were inserted in both renal arteries as fluoroscopic landmarks. A 12-mm iliac extension served as the canine aortic endograft. The first procedure was done under ultrasound and fluoroscopic guidance, using an intravascular ultrasound (IVUS) probe inserted in the vena cava and a Pioneer IVUS catheter. The second was performed exclusively under fluoroscopic guidance with a Brockenbrough needle. Angiograms and duplex ultrasound were planned for 1 month, after which the dogs would be sacrificed for autopsy. The explanted endograft was subjected to biomaterials analysis, with a focus on fabric tear.

Results:

Perforation of the aortic graft and catheterization of the renal arteries with a floppy guidewire were possible in both animals. In dog 1, aortic graft dilation and subsequent fenestration were not possible, and the experiment was terminated. However, the procedure was successful in both renal arteries of dog 2. At 1-month follow-up in this dog, both renal arteries were patent. Stent fractures were observed bilaterally. There was no extension of the damage to the fabric beyond the area of fenestration.

Conclusion:

In vivo antegrade fenestration of aortic endografts is technically feasible. However, improvements in technique, instrumentation, and materials are required to make it a reliable and reproducible way of allowing stent-graft vascularization of aortic side branches.

In Situ Fenestration Through the Contralateral Iliac Artery to Convert an Aortouni-iliac Into a Bifurcated Endograft

Purpose: To present a technique of in situ fenestration that allows conversion of an aortouni-iliac endograft into a bifurcated endograft, thereby avoiding crossover femorofemoral bypass and its complications. Technique: Following conventional deployment of an aortouni-iliac endograft, in situ fenestration through the contralateral common iliac artery is performed with a transjugular intrahepatic access set. The fabric hole is enlarged using a cutting balloon and a high-pressure noncompliant balloon. Kissing iliac-covered stents are then positioned at the level of the bifurcation to convert the aortouni-iliac endograft into a bifurcated repair. To date, this technique has been successfully used in 4 patients with satisfactory short-term results. Conclusion: This technique represents another application of endograft in situ fenestration. This strategy provides a bifurcated repair in cases where bifurcated stent-grafts are usually precluded, such as a narrow distal aorta, ruptured abdominal aortic aneurysm, or combined aortoiliac occlusive disease.

In Situ Stent-Graft Fenestration to Preserve the Left Subclavian Artery

PURPOSE

To report our first clinical application of a new technique for in situ fenestration of a thoracic stent-graft.

CASE REPORT

After completing a series of in vitro and in vivo experiments, in situ stent-graft fenestration was employed during endograft repair of a saccular thoracic aortic aneurysm in a 77-year-old woman. Because the stent-graft would have covered the left subclavian artery ostium, a modified Zenith TX1 thoracic stent-graft was deployed then fenestrated transluminally using a guidewire followed by serial cutting balloons, which created a fenestration over the LSA sufficiently large to accommodate a Jomed covered stent on an 8-mm balloon. Completion angiography showed exclusion of the aneurysm and brisk flow into the LSA. Following the procedure, the arm pressures were nearly equal. The 6-month CT scan showed no endoleak and a patent subclavian artery stent.

CONCLUSIONS

In situ graft fenestration to preserve the left subclavian artery after deliberate coverage during endovascular repair of a thoracic aortic aneurysm appears feasible in this initial clinical application. There are uncertainties regarding the long-term stability of the fabric tears that are an inherent part of this technique.