Clinical Effectiveness of an Off-the-shelf Single REnal Scalloped sTent-graft for HOstile NEck Infrarenal Abdominal Aortic Aneurysm

Study Overview
=================
Brief Summary
-----------------
The goal of this multicenter, observational cohort study is to evaluates the clinical effectiveness of a single-renal scallop custom-made stent-graft (TREO, Terumo Aortic, Sunrise, FL) to treat hostile AAA with mismatched renal arteries as actual standard of care in this Vascular Unit The main question it aims to answer are: if a dedicated devices could improve the results in the endovascular treatment of patients suffering to infrarenal abdominal aortic aneurism with a mismatched takeoff of the renal arteries. Participants responding to inclusion criteria will be treated as best clinical practice with a custom made device with a single scallop for the renal artery. The minimum follow-up requested, as standard clinical practice, was: 3-months, 12-18 months- and 5-years CTA; clinical and DUS examination at 6- and 12- and 36-months after the intervention and yearly thereafter. No comparison group was present.

Detailed Description
-----------------
Endovascular aneurysm repair (EVAR) is currently the preferred choice to treat the abdominal aortic aneurysms (AAA) with a feasible anatomy. However, approximately 40-60% of AAA patients presented unfavorable characteristics for EVAR, mainly due to a hostile neck anatomy. In ''real-world'' clinical practice, up to 44% of EVAR cases are performed outside Instruction For Use (IFU) for an adverse neck anatomy6. Short (<15-mm), angulated (>60°), and wide (>28-mm) aortic necks are the main features concurring to the proximal HNA. The recourse to standard EVAR is currently routine for patients who are not eligible for OR, with acceptable short- and mid-term outcomes, but the long-term durability of EVAR depends on maintaining proper sealing between the endograft and the aortic neck as well as the iliac arteries. HNAs demonstrated worse results when compared to favorable ones in terms of technical success (94% vs. 98%) and type-Ia endoleak rate (10% vs. 2%). The issue linked to an unfavorable anatomy can be addressed with more complex techniques, but these are limited by high production costs and considerable complexity . TREO (Terumo Aortic, Inchinnan, Renfrewshire, UK; formerly Treovance, Bolton Medical, Sunrise, Fla) is a standard bifurcated, modular stent-graft that has shown compelling early- and mid-term results. It seems clear that several physicians are still looking for a feasible solution for HNA patients to keep the complexity of the procedure comparable to standard EVAR while yielding improved results. Moreover, there is a lack of publications addressing the issue of mismatched take-off of the renal arteries (RAs). This morphology seems to influence the sealing length and could justify the introduction of dedicated devices. A recent study from our group currently under review for publication demonstrated that 25% of patients eligible for EVAR presented with mismatched RAs and that a dedicated device could improve sealing significantly. The study group sealing zone's length increased by about 25% when applying a hypothetical prototype with a single 10x10mm (wide x high) renal scallop. The same approach could be applied to the sealing surface with similar results. In the light of obtained results in selected patients, the use of a single renal-scallop custom-made device has been our standard of care. The results will demonstrate whether the supra mentioned graft can the treatment of AAA with mismatched RAs in the real world. The effectiveness will be evaluated in terms of technical and clinical success. The benefits could be relevant for the patients in terms of reduction of procedure-related adverse events such as endoleaks and related re-interventions. Furthermore, the use of custom-made standardized devices could significantly reduce costs for health care providers and in the future, it could be the base for an off-the-shelf endograft. Procedure-related complications were expected to be similar to standard EVAR and reduced in comparison with literature reporting adverse events in more complex techniques. The present study aims to evaluate the clinical effectiveness of the custom-made standardized single renal scalloped stent-graft (Treo, Terumo Aortic) to treat infrarenal AAA. The final objective will be to employ the data obtained in this cohort for a future eventual development of an off-the-shelf device dedicated to patients with mismatched renal arteries. Such an endograft could keep the complexity of the procedure as similar as possible to standard EVAR while improving sealing.

Official Title
-----------------
Clinical Effectiveness of an Off-the-shelf Single REnal Scalloped sTent-graft for HOstile NEck Infrarenal Abdominal Aortic Aneurysm: Clinical Pivotal Trial

Conditions
-----------------
Abdominal Aortic Aneurysm

Intervention / Treatment
-----------------
* Device: Endovascular Aortic Repair (EVAR)


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patients affected by infrarenal AAA > 50mm Treated in election for non-symptomatic AAA Anatomy inside Treo (Terumo Aortic) instruction to use (IFU) Distance between renal arteries >10mm on aortic center-lumen-line Age > 18 Patient fit to plead Both sex Written informed consent Treated in the coordinator center or in one of the study's participating centers Minimum follow-up requested: 3-months, 12-18 months and 5-years CTA; clinical and DUS examination at 6- and 12- and 36-months after the intervention and yearly thereafter Exclusion Criteria: Patients with aortic pathologies different from AAA (aortic ulcers, dissection, pseudo-aneurysm etc) Treated in urgent/emergent setting for symptomatic or ruptured AAA AAA < 50mm Outside TREO (Terumo Aortic) IFU With an inter-renal distance measured of the center-lumen-line <10mm Age <18 Unfit to plead Refused to sign the informed consent Treated outside the coordinator centers or in one of the study's participating center's Refusal to adhere to the requested follow-up

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| AAA patients with a mismatched takeoff of the renal arteries candidated to standard EVAR<br>Patients suffering to AAA with a mismatched takeoff (>10mm) of the renal arteries | Device: Endovascular Aortic Repair (EVAR)<br>* Techniques for delivery and deployment of the standard device have been well described by different papers, but for the prototype some attention is required. Once the device was advanced at the level of the lowest RA the C-Arm has been moved to correct the parallax effect and positioned orthogonally to the origin of the artery. This procedure permits perfectly matching the scallop with the artery takeoff. A selective angiogram was performed to assure the patency of the lower RA. After the deployment of the main body proper iliac extensions were delivered to completely exclude the aneurysm as standard practice.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evaluation of the clinical effectiveness of the endovascular exclusion of infrarenal Abdominal Aortic Aneurysm with a single renal scallop endograft | Clinical effectiveness measured in terms of technical and clinical success. Technical success was defined as successful introduction and deployment of the device in the absence of surgical conversion or mortality, type I or III endoleaks, or graft limb obstruction. A technical success thus implies the following qualifying details: 1. Successful access to the arterial system using a remote site; 2. successful deployment of the endoluminal graft with secure proximal and distal fixation; 3. absence of either a type I or III endoleak; 4. patent endoluminal graft without significant twist, kinks, or obstruction by intraoperative measurements; 5 patency of both renal arteries and at least one hypogastric artery. | up to 24 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evaluation of the intra-operative and peri-operative (within 30 days) adverse events |  | up to 30 days | 
| Collection of eventual adverse events related to the treatment procedure and eventual post-hoc analysis |  | through study completion, an average of 2 years. | 
| Evaluation of reintervention rate |  | through study completion, an average of 2 years. | 
| Evaluation time elapsed from procedure to re-intervention |  | through study completion, an average of 2 years. | 
| Evaluation of the association between baseline and anatomical features to adverse technical success, clinical success and reintervention rate |  | through study completion, an average of 2 years. | 
| Evaluation of the average procedural time |  | up to 24 hours | 
| Evaluation of the average fluoroscopy time |  | up to 24 hours | 
| Evaluation of the average contrast medium (CM) |  | up to 24 hours | 
| Evaluation of the average dose absorption (DAP) mGy/m3 |  | up to 24 hours | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
AAA, EVAR, Hostile Neck Anatomy