Antegrade In Situ Stent-Graft Fenestration for the Renal Artery Following Inadvertent Coverage During EVAR

Renal rescue after inadvertent coverage during endovascular aneurysm repair

Inadvertent renal artery obstruction during endovascular aortic repair is a rare but serious complication. In such cases, endovascular recanalization is typically attempted; however, it can be challenging, leading to many severe cases. Moreover, if treatment is delayed, the blockage time of the renal artery poses a problem. We encountered a case of inadvertent renal artery occlusion during endovascular aortic repair. In this case, bailout stent implantation through a gap between the aortic wall and a stent graft made by a balloon catheter was effective in reducing the renal ischemia time and facilitating the revascularization procedure.

Advanced Endovascular Treatment of Complex Aortic Pathology

Endovascular aortic aneurysm repair and thoracic endovascular aortic repair have been shown to reduce blood loss, operative time, length of hospital stay, mortality, and morbidity compared with open surgical repair for abdominal aortic aneurysms and thoracic aortic aneurysms. However, there are anatomical constraints that limit the application of the endovascular approach in 30% to 40% of patients, including those with short necks, excessive angulation, or aneurysms with the involvement of aortic side branches such as supra-aortic trunks, arch aneurysms, visceral arteries, or internal iliac arteries.

Stent-Graft Fabrics Incorporating a Specific Corona Ready to Fenestrate

In situ fenestration of endovascular stent-grafts has become a mainstream bailout technique to treat complex emergent aneurysms while maintaining native anatomical visceral and aortic arch blood supplies. Fabric tearing from creating the in situ fenestration using balloon angioplasty may extend beyond the intended diameter over time. Further tearing may result from the physiologic pulsatile motion at the branching site. A resultant endoleak at the fenestrated sites in stent-grafts could ultimately lead to re-pressurization of the aortic sac and, eventually, rupture. In an attempt to address this challenge, plain woven fabrics were designed. They hold a specific corona surrounding a square-shaped cluster with a plain weave fabric structure, a 2/2 twill, or a honeycomb. The corona was designed to stop potential further tearing of the fabric caused by the initial balloon angioplasty and stent or later post-implantation motion. The cluster within the corona was designed with relatively loose fabric structures (plain weave, 2/2 twill weave, and honeycomb) to facilitate the laser fenestration. Two commercial devices, Anaconda (Vascutek, Terumo Aortic) and Zenith TX2 (Cook), were selected as controls for comparison against this new design. All the specimens were characterized by morphology, thickness, and water permeability. The results demonstrated that all specimens with a low thickness and water permeability satisfied the requirements for a stent graft material that would be low profile and resistant to endoleaks. The in situ fenestrations were performed on all fabrics utilizing an Excimer laser followed by balloon angioplasty. The fabrics were further observed by light microscopy and scanning electron microscopy. The dimension of the fenestrated apertures was smaller than the balloon's diameter. The tearing was effectively confined within the corona. The clinical acceptability of this concept deserves additional bench testing and animal experimentation.

Antegrade in situ laser fenestration of aortic stent graft during endovascular aortic repair: A case report

BACKGROUND

The endovascular repair of juxtarenal abdominal aortic aneurysms (JAAA) usually requires combination treatment with various stent graft modifications to preserve side branch patency. As a feasible technique, according to the situation, antegrade in situ laser fenestration still needs to be improved.

CASE SUMMARY

This report describes a case that was successfully treated with endovascular repair facilitated by antegrade in situ laser fenestration while maintaining renal arterial flow. Laser fenestration was performed using a steerable sheath positioned in the stent graft lumen in front of the renal artery ostium. With the bare stent region unreleased, renal artery perfusion could be maintained and accurate positioning could be achieved by angiography in real time.

CONCLUSION

This study suggests the feasibility and short-term safety of this novel antegrade in situ laser fenestration technique for select JAAA patients.

Rapid endovascular bailout revascularization of the renal arteries with a steerable guiding sheath after endovascular abdominal aortic aneurysm repair

Advancements in endovascular therapy have made it increasingly available for patients with complex cases but not without complications. Unintentional coverage of the renal arteries is a rare occurrence during endovascular aortic aneurysm repair. Given the potentially devastating repercussions, it is important that surgeons understand the suitability and the risks and benefits of the available revascularization options. We have described two cases of unintentional renal coverage, with subsequent successful bailout via direct manipulation of the stent-graft with a steerable sheath. We also conducted a review of the reported data, discussed the breadth of management options and their technical aspects, and provided several distinct solutions.

Optimal In Situ Fenestration Technique With Laser Perforation and Balloon Dilation for Aortic Stent-Grafts

PURPOSE

To evaluate the response of various stent-grafts after laser fenestration and dilation with noncompliant balloons to determine the optimal therapeutic combination for this treatment technique.

MATERIALS AND METHODS

Five aortic stent-grafts were evaluated ex vivo: the Bolton RelayPlus, Jotec E-vita Thoracic 3G, Medtronic Valiant, Cook Zenith Alpha, and Vascutek Anaconda. Small holes were created using an excimer laser with the grafts submerged in saline. Five rows of 5 fenestrations were created, 4 holes in each row were dilated once with a 6-, 8-, 10-, or 12-mm-diameter noncompliant balloon to the specified nominal pressure (one hole served as the control). The saline solution from each stent-graft was collected and qualitatively analyzed for debris. The fenestrations were evaluated under light and scanning electron microscopes. The maximum diameter and area for each fenestration were measured. The direction and length of tears were assessed.

RESULTS

The fenestration was feasible and reproducible in all the stent-grafts. The mean area of fenestration ranged from 7.63±1.63 to 14.75±0.73 mm² when using balloons of 6- and 8-mm diameter, respectively. The 10- and 12-mm-diameter balloons caused a significant increase in area, variability, and tearing. The Anaconda graft tended to tear in the weft direction, while the other devices tore in the warp direction when using the 10- and 12-mm-diameter balloons. Dilation of the RelayPlus and Anaconda grafts with 6- and 8-mm-diameter balloons provided minimal tearing and precise fenestrations. Melted fiber remnants were observed after filtration of the saline solution for all devices.

CONCLUSION

Laser fenestration and dilation with noncompliant balloons is a relatively simple and reproducible option for revascularization in urgent, complex aortic endovascular repairs. In our model, large balloons (ie, >10 mm) increased the destruction and tearing of the fabric. The maximum dilation recommended is 6 to 8 mm to avoid significant tears. Development of stent-grafts or novel fabrics designed explicitly for fenestration is needed to reduce potential complications.

Total Endovascular Arch Repair Using Needle Fenestration and Extracorporeal Membrane Oxygenation

There remains a clinical need for endovascular repair of the ascending aorta and the aortic arch in patients who are prohibitively high risk for open surgical repair. Herein we present a case of a total endovascular arch repair by means of a novel technique for graft fenestration using a trans-septal needle with extracorporeal membrane oxygenation support. Although the use of trans-septal needle fenestration use has been described, the use in arch fenestrations has not. We present this case as an example of techniques that may be useful in the expanding landscape of endovascular ascending and arch repair.

Salvage of bilateral renal artery occlusion after endovascular aneurysm repair with open splenorenal bypass

We report renal salvage maneuvers after accidental bilateral renal artery coverage during endovascular aneurysm repair of an infrarenal abdominal aortic aneurysm. A 79-year-old man with an infrarenal abdominal aortic aneurysm was treated with endovascular aneurysm repair. Completion angiography demonstrated coverage of the renal arteries. Several revascularization techniques were attempted, including endograft repositioning and endovascular stenting through the femoral and brachial approach. The patient eventually underwent open splenorenal bypass with a Y Gore-Tex graft (W. L. Gore & Associates, Flagstaff, Ariz). After 3 months, computed tomography showed no evidence of endoleak and patent renal arteries. Renal function was well maintained, and the patient did not require dialysis.

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 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.