Clinical Experience with a Customized Fenestrated Endograft for Juxtarenal Abdominal Aortic Aneurysm Repair

Three-year outcomes of off-the-shelf Gore thoracoabdominal multibranch endoprosthesis and physician-modified endografts for complex abdominal and thoracoabdominal aortic aneurysms

OBJECTIVE

Fenestrated-branched endovascular aortic repair (FB-EVAR) has shown favorable outcomes for repair of complex aneurysms and thoracoabdominal aortic aneurysms. Physician-modified endografting (PMEG) and the Gore thoracoabdominal multibranch endoprosthesis (TAMBE) provide custom and off-the-shelf devices for FB-EVAR, respectively. This study compares the outcomes of TAMBE and PMEG at a single institution.

METHODS

A retrospective review of patients who underwent TAMBE as part of the multicenter pivotal trial or PMEG as part of a prospective physician-sponsored investigational device exemption at a single institution between 2020 and 2022 were completed. Patient demographics, characteristics, and perioperative and midterm outcomes were compared.

RESULTS

A total of 68 patients were included, with 12 in the TAMBE group and 56 in the PMEG group. Baseline characteristics were comparable between groups. Aneurysm type was most often thoracoabdominal aortic aneurysm in both groups (58% TAMBE and 52% PMEG). TAMBE had a higher rate of upper extremity access (100% vs 63%; P = .013) and longer mean procedure time (247 ± 36 minutes vs 189 ± 49 minutes; P < .001). Other intraoperative metrics were similar between groups. Technical success was 100% in TAMBE and 95% in PMEG (P = .412). There was no 30-day mortality in either group. No major adverse events occurred with TAMBE, whereas in PMEG cases, 2% had respiratory failure, 2% required dialysis, and 4% experienced spinal cord ischemia. Although the overall endoleak rates were similar (50% of TAMBE vs 41% of PMEG; P = .57), type II endoleaks accounted for all of the endoleaks in the TAMBE group, whereas type I or III endoleaks were seen in 11% of PMEG patients. At a median follow-up of 26.7 months for the TAMBE group and 21.2 months for the PMEG group, target vessel instability was seen in 10.4% of TAMBE, and 6.9% of PMEG targeted branches (P = .401). Reintervention was required in 33% of TAMBE patients and 27% of PMEG patients (P = .646). Estimated freedom from reintervention rates at 3 years were similar (56% TAMBE vs 62% PMEG, log-rank P = .910). Freedom from visceral renal target vessel instability at 3 years was 89% for both groups (log-rank P = .459). The Kaplan-Meier 3-year estimated survival was 100% for patients in the TAMBE group and 77% for patients in the PMEG group (log-rank P = .157).

CONCLUSIONS

At experienced centers, FB-EVAR can be completed with PMEG or TAMBE with comparable, excellent perioperative and midterm outcomes. Reinterventions are frequently needed for both TAMBE and PMEG.

Physician-Modified Endografts for Repair of Complex Abdominal Aortic Aneurysms: Clinical Perspectives and Medico-Legal Profiles

Standard endovascular aortic repair (EVAR) has become the standard of care for treating infrarenal abdominal aortic aneurysms (AAAs) in patients with favorable anatomies, while patients with challenging AAA anatomies, and those with suprarenal or thoraco-abdominal aneurysms, still need alternative, more complex, solutions, including custom-made branched or fenestrated grafts, which are constrained by production delay and costs. To address urgent needs and complex cases, physicians have proposed modifying standard endografts by manually creating graft fenestrations. This allows for effective aneurysm exclusion and satisfactory patency of visceral vessels. Although physician-modified grafts (PMEGs) have demonstrated high technical success, standardized creation processes and long-term safety data are still lacking, necessitating further study to validate their clinical and legal standing. The aim of this article is to illustrate the state of the art with regard to this surgical technique, summarizing its origin, evolution, and the main clinical evidence supporting its effectiveness. The paper also aims to discuss the main medico-legal issues related to the use of PMEGs, with particular reference to the issue of safety related to the standardization of the surgical technique, medical liability profiles, and informed consent.

[Acute Complex Endovascular Aortic Repair - Off-the-shelf vs. Surgeon-modified Stent Grafts]

INTRODUCTION

Treatment of complex abdominal and thoracoabdominal aortic aneurysms is challenging. Open surgical repair is a high-risk operation, especially in emergency cases. Endovascular aneurysm repair with a patient-specific custom-made stent graft in patients with symptomatic or ruptured complex aortic aneurysms is not possible, due to the manufacturing time required. In such cases, alternative endovascular techniques can be used.

RESULTS

The "off-the-shelf" and "surgeon-modified" stent grafts are valid options for the endovascular treatment of complex aneurysms in urgent and emergent patients. The former are standardised commercially manufactured fenestrated or branched stent grafts, which are available off-the-shelf with an anatomical feasibility in 50 - 80% of the patients. The "surgeon-modified" stent grafts refer to a technique, in which a commercially available stent graft is modified by the surgeon under sterile conditions directly before the implantation, in order to add the required fenestrations, scallops and/or branches. The modification takes approximately 60 - 120 min and haemodynamic stability of the patient is mandatory. Because of the off-label use of the commercial stent graft, detailed patient consent about the modification complications and risks should be performed whenever possible. A comparison of results on mortality and morbidity between "off-the-shelf" and "surgeon-modified" stent grafts has been published, although a direct comparison would be unfair for several reasons (different design, lack of extensive outcomes reports, long learning curve and different modification techniques).

CONCLUSION

The "surgeon-modified" and "off-the-shelf" fenestrated/branched stent grafts are used in the treatment of high-risk patients with symptomatic or contained ruptured complex aneurysms. The outcomes of the two techniques are good, although the long-term durability of the former should be further investigated.

[Surgeon-modified Stent Grafts for Complex Aortic Reconstructions - What is Feasible?]

BACKGROUND

The close anatomical relationship to the visceral vessels renders the treatment of complex throacoabdominal aortic pathologies challenging. In emergent cases, off-the-shelf stent grafts and parallel techniques are feasible treatment options. Alternatively, the treating surgeon can alter a conventional stent graft, creating a so-called surgeon-modified stent graft (SMSG) to adapt it to the complex aortic pathology. The aim of this publication is to present the possibilities and results of this method.

RESULTS

The location of SMSG's fenestrations can be determined after manual measurements of the centerline of flow reconstructions of the aortic computed tomography-angiography. The planning of the SMSG can be simplified and standardized by creating personalized 3D aortic models, and by using algorithms for the automated determination of the ideal fenestration positions. Most approved stent grafts can be used as platforms for SMSG. Different manufacturing techniques have been described. In addition to simple fenestrations, mini-cuffs, directional branches, and inner branches are used. Furthermore, diameter reducing ties and preloaded catheters could facilitate the implantation. The treatment of complex aortic pathologies using SMSG has achieved good results, with high technical success rate of 90-100%, and low 30-day mortality, especially when compared to open surgical treatment of similar patients. The rate of endoleak of 0-14% was also acceptable. Long-term durability results after treatment with SMSG are not yet available.

CONCLUSION

Surgeon-modified stent grafts are safe and feasible for the endovascular treatment of patients with urgent complex thoracoabdominal aortic pathologies. They represent compassionate use and show promising results in the published literature.

Experience with physician-modified Ankura™ endografts for endovascular repair of thoracoabdominal aortic aneurysms

BACKGROUND

The aim of this study was to evaluate the early results of fenestrated/branched endovascular aortic repair (F/B-EVAR) of thoracoabdominal aortic aneurysms (TAAAs) using physician-modified Ankura^™ endografts (PMEGs).

METHODS

Sixteen consecutive patients who underwent F/B-EVAR using PMEGs between July 2017 and December 2018 were retrospectively reviewed. The perioperative mortality and morbidity of the PMEG technique were assessed, and the early results of follow-up were evaluated.

RESULTS

The median age of the patients was 75.3 years old (range: 48-83 years), and 12 (75.0%) patients were male. The median TAAA diameter was 7.1±1.5 cm (range: 5.1-11 cm). The initial technical success rate of vessel revascularization was 98.2% (55 of 56). Target vessel patency was 98.1% (52/53), and freedom from reintervention was 98.1% (52/53) at follow-up. The 30-day mortality rates 6.3%. There was no death during follow-up.

CONCLUSIONS

PMEGs represent an important innovation, with favorable initial results, in the treatment of patients with complex TAAAs who may be unfit for open repair. In addition, they remain a promising option for high-risk patients in need of urgent repair who cannot wait for a custom-made device.

Comparison of Physician-Modified Fenestrated/Branched Stent-Grafts and Hybrid Visceral Debranching Plus Stent-Graft Placement for Complex Thoracoabdominal Aortic Aneurysm Repair

Purpose: To evaluate the immediate postoperative and midterm outcomes of complex thoracoabdominal aortic aneurysm (TAAA) treatment with fenestrated/branched physician-modified endovascular grafts (PMEGs) or open debranching of the visceral aorta with bypass graft revascularization plus endovascular aneurysm exclusion (hybrid repair). Materials and Methods: A retrospective analysis was conducted of 88 patients (mean age 70.0±10.6 years; 73 men) with complex TAAAs who underwent treatment with PMEGs (60, 68%) or a hybrid technique (28, 32%) between 2016 and 2019. The mean aneurysm diameter was 64.5±11.7 mm, and 37 patients (42%) were symptomatic. The Zenith TX2 and Ankura were the main stent-grafts used in the PMEG group. The hybrid technique involved visceral debranching with extra-anatomical bypass graft revascularization and subsequent stent-graft deployment (1- or 2-stage procedure). Results: In the PMEG group, 35 patients received modified stent-grafts with 4 fenestrations, 8 patients had 4 branches per device, and 17 patients had combinations (50 fenestrations and 18 branches) that successfully revascularized 228 of the 240 targets (95%). In the 28 hybrid cases, all 110 target vessels were successfully revascularized with bypass grafts. The overall 30-day mortality was 3.4% (2 PMEG and 1 hybrid), and the early rate of target vessel stenosis/occlusion was 3.3% (5 in PMEG group and 6 in the hybrid repair group). The 30-day morbidity was mainly attributed to pulmonary complications (15%), lower limb ischemia (8%), or spinal cord ischemia with paraplegia (6%). Eleven patients (13%) had deteriorated renal function with a >30% decrease in the glomerular filtration rate. The mean follow-up was 22.3±4.9 months, and mortality was 4.5% (3.3% in the PMEG group vs 7.1% in the hybrid repair group). Conclusion: PMEGs and hybrid techniques seem to be feasible treatment options for aortic aneurysms necessitating visceral vessel revascularization. PMEGs may have a lower morbidity than the hybrid technique, which nonetheless remains an important option available for complex aortic aneurysms.

Physician-Modified Fenestrated Endografts for Managing the Ruptured or Symptomatic Aortic Aneurysm: Technique Overview and Clinical Outcomes

PURPOSE:

Fenestrated endovascular aneurysm repair (FEVAR) grafts have a 10- to 12-week manufacturing time and are generally not available for emergency cases of symptomatic or ruptured aortic aneurysm. In the absence of other alternatives, conventional off-the-shelf stent grafts can be modified by trained operators to treat these complex cases. The aim of this study is to present a single-center experience of physician-modified FEVAR.

METHODS:

A retrospective review was performed of all physician-modified FEVAR identified from the hospital endovascular database at a single tertiary referral center between September 1996 and September 2017.

RESULTS:

Eight cases of urgent or emergency endovascular aneurysm repair (EVAR) with physician-modified grafts were identified. Mean follow-up was 44 weeks (range: 5-106 weeks). Outcomes for all implanted grafts (7/8 cases) included 100% technical success, 14% rate of endoleak, no procedure-related complications, no adverse visceral events, 0% 30-day mortality and 100% 1-year target vessel patency, and freedom from aneurysm-related death. There was a 14% (1/7 cases) per patient reintervention rate.

CONCLUSION:

Modifying EVAR grafts is a highly technical process requiring meticulous planning and extensive elective experience with FEVAR. The current series demonstrates that physician modification of endografts for urgent or emergency abdominal aortic aneurysm repair is feasible and a safe alternative to open surgical aneurysm repair.

3D printing guiding stent graft fenestration: A novel technique for fenestration in endovascular aneurysm repair

Objective To describe a novel approach, 3D printing guiding stent graft fenestration, for fenestration during endovascular aneurysm repair for juxtarenal abdominal aortic aneurysm. Methods A 69-year-old male with juxtarenal abdominal aortic aneurysm underwent endovascular aneurysm repair with "off the label" fenestrated stent graft. To precisely locate the fenestration position, we reconstructed a 3D digital abdominal aortic aneurysm model and created a skin template covering this abdominal aortic aneurysm model. Then the skin template was physically printed and the position of the visceral vessel was hollowed out, thereby helping in locating the fenestration on stent graft. Results and conclusions With the help of this 3D printed skin template, we fenestrated the stent graft accurately and rebuilt the bilateral renal artery successfully. This is the first clinical case that used 3D printing guiding stent graft fenestration, which is a novel approach for precise fenestration on stent graft on the table during endovascular aneurysm repair.

Application of physician-modified fenestrated stent graft in urgent endovascular repair of abdominal aortic aneurysm with hostile neck anatomy: Case report

BACKGROUND

This study aimed to evaluate the feasibility and effectiveness of the Gore Excluder aortic stent graft (WL Gore & Associates, Inc., Flagstaff, AZ) using the C3 Delivery System after physician modification of fenestration for the urgent treatment of patients with abdominal aortic aneurysm showing hostile neck anatomy.

CASE SUMMARY

Three urgent cases of abdominal aortic aneurysm with hostile neck anatomy symptom with abdominal pain were reported. The same fenestration method was applied to align the target superior mesenteric artery and bilateral renal arteries with 1 scallop and 2 fenestrations, followed by the reconstruction of the target artery using a bare-metal stent or stent graft. Balloon-assisted positioning and image fusion technology were intraoperatively applied to assist the accurate release of the stent graft body. The follow-up periods for all cases exceeded 6 months, showing smooth circulation in the target arteries with no endoleaks.

CONCLUSION

In the absence of other available treatment methods, it is feasible to use a stent graft with physician-modified fenestration for the urgent endovascular repair of abdominal aortic aneurysm with hostile neck anatomy. However, this procedure's long-term efficacy needs to be further investigated.

Systematic Review of Off-the-Shelf or Physician-Modified Fenestrated and Branched Endografts

Purpose: To determine the safety and efficacy of off-the-shelf fenestrated/branched grafts (OSFGs) and physician-modified stent-grafts (PMSGs) for the treatment of complex abdominal aortic aneurysms. Methods: A systematic search of the MEDLINE database via PubMed from January 2001 through March 2015 retrieved 23 relevant articles evaluating the clinical outcomes following the management of patients with pararenal or thoracoabdominal aortic aneurysms. The 15 articles on PMSGs and 8 on OSFGs contained data on 308 patients (mean age 72.93±2.89 years; 213 men). The safety endpoint was major adverse events; the efficacy outcome measure was clinical treatment success (aneurysm exclusion without type I/III endoleak, permanent paralysis, long-term dialysis, or unresolved major complications). Extracted outcome data were pooled and compared between groups; data are given as the pooled proportions and 95% confidence interval (CI). Clinical data are presented as the weighted mean. Results: Of the 308 patients analyzed, almost one third were operated on an emergency basis. The mean aneurysm diameters were 75.9±17.3 mm (range 56–115) for the PMSGs and 68.1±13.7 mm (range 60–100) for the OSFGs. A total of 936 renal and visceral vessels were targeted. Major adverse events (safety) occurred in 24 (12.8%) PMSG patients (95% CI 8.6% to 18.7%) and in 9 (7.4%) OSFG patients (95% CI 3.7% to 14%). Clinical treatment success (efficacy) was observed in 171/187 (91.4%) PMSG patients (95% CI 86.2% to 94.9%) and in 115/121 (95%) OSFG patients (95% CI 89.1% to 98.0%). Corresponding cumulative 30-day target vessel and branch stent perfusion rates were 97.2% (95% CI 95.1% to 98.4%) and 97.6% (95% CI 95.5% to 98.8%) for the PMSG group and 99.6% (95% CI 98.3% to 99.9%) and 98.4% (95% CI 96.5% to 99.4%) for the OSFG group. Six (3.2%) deaths occurred in the PMSG group only; 2 (1.1%) were aneurysm related. Overall branch patency was recorded in 443/458 (96.7%) and in 468/478 (97.9%) of target vessels in the PMSG and OSFG groups, respectively. Conclusion: Off-the-shelf and physician-modified technology seems effective and safe, in both the elective and acute settings, for the treatment of complex aortic aneurysms. Future research within a randomized trial should investigate the true limitations of these devices.

Renal autotransplant for subsequent endovascular exclusion of the thoracoabdominal aorta

In the last 20 years, endovascular procedures have radically altered the treatment of diseases of the aorta. The objective of endovascular treatment of dissections is to close the entry point to redirect blood flow toward the true lumen, thereby achieving thrombosis of the false lumen. In extensive chronic dissections that have evolved with the formation of a large aneurysm, the dissection is maintained from the end of the endoprosthesis due to multiple orifices, or reentries, that communicate with the lumens. In addition, one of the primary limitations of this technique is when the visceral arteries have disease involvement. In this report we present a case where, despite having treated the entire length of the descending thoracic aorta, the dissection was maintained distally, leading to progression of the diameter of the aneurysm. After reviewing the literature, and to the best of our knowledge, we describe the first case in which renal autotransplant was performed to allow for subsequent exclusion of the aorta at the thoracoabdominal level using a fenestrated endoprosthesis for the celiac trunk and the superior mesenteric artery.

Preprocedural planning for endovascular stent-graft placement

Endovascular stent grafts have become a viable treatment for aortic thoracic and abdominal aneurysms in both elective and emergent situations. Computed tomographic (CT) angiography is the primary tool for determining eligibility for this procedure. This article discuses the preprocedural evaluation of an endovascular stent candidate. Evaluation begins with identification of the aneurysm pathology and its relationship to treatment efficacy. The radiologist must evaluate the aneurysm geometry for compatibility with stent hardware. Aneurysm features that suggest a contraindication must be recognized. Procedures that involve a combination of endovascular stenting and surgical revascularization are discussed so that the reader understands the limits of stent eligibility. Vascular access for stent placement must also be evaluated for the ability to accommodate stent delivery. The radiologist also must be familiar with CT imaging protocols and alternative methods of imaging that can evaluate stent feasibility. The utility of three-dimensional processing is discussed.

Technique of Adding a Diameter-reducing Wire to the Modified TX2 Fenestrated Stent Graft

One of the technical limitations of surgeon-modified fenestrated stent grafts is the lack of a diameter-reducing wire, which facilitates catheterization of target branches if there are errors of device design, alignment, or implantation. This article describes a technique of adding a diameter-reducing wire to the modified TX2 fenestrated stent graft for compassionate use in aortic emergencies or high-risk patients who do not have access to manufactured devices. The modified Cook TX2 stent graft was created using reinforced fenestrations with gold nitinol markers. After the TX2 stent was fully unsheathed, one of the nitinol wires located in the inner cannula was withdrawn and redirected externally through and through the fabric of the stent graft. Each Z stent was constrained using the nitinol wire for support and two nonlocking polypropylene loops. The use of a diameter-reducing wire facilitates side branch catheterization by allowing longitudinal and rotational movement to the modified fenestrated stent graft in patients where there is misalignment between the fenestration and the origin of the target vessel.

Changing Indications and Outcomes for Open Abdominal Aortic Aneurysm Repair since the Advent of Endovascular Repair

The indications for open abdominal aortic aneurysm (AAA) repair have changed with the development of endovascular techniques. The purpose of this study is to clarify the indications and outcomes for open repair since endovascular aneurysm repair (EVAR) and to compare contemporary AAA repair with the pre-EVAR era. Patients undergoing open AAA repair were identified; the demographics, outcomes, and indications for open repair were reviewed. Outcomes were compared based on indication for open repair in the EVAR era and between the pre-EVAR and EVAR eras. Open indications in the EVAR era included: age younger than 65 years with minimal comorbidities (AGE, n = 24 [9.8%]), unfavorable anatomy (ANAT, n = 146 [59.3%]), aortoiliac occlusive disease (AIOD, n = 38 [15.4%]), and miscellaneous (OTHER, n = 38 [15.4%]). Mortality (30-day and 5-year) was affected by indication: AGE = 0 and 0 per cent, ANAT = 4.1 and 49.7 per cent, AIOD = 13.5 and 32.3 per cent, and OTHER = 5.3 and 41.8 per cent. Age, sex, race, coronary artery disease, and peripheral artery disease were similar between the pre-EVAR and EVAR eras. EVAR-era patients had more diabetes mellitus, hypertension, and hyperlipidemia and longer operative time. Mortality was not different, but complication rates were lower in the pre-EVAR era (23.7 vs 43.5%, P = 0.025). Patients undergoing open AAA repair in the EVAR era have more comorbidities, longer operative times, and more complications. Outcomes for EVAR-era patients are affected by the indication for open repair. A preference for open repair in younger patients with minimal comorbidities is justified.