Kilt Technique as an Angle Modification Method for Endovascular Repair of Abdominal Aortic Aneurysm with Severe Neck Angle

Case Report: Emergency endovascular management of a ruptured giant abdominal aortic aneurysm with severely angulated and conical shaped neck using novel multiple stiff wire technique

Background

Ruptured abdominal aortic aneurysm (rAAA) is commonly fatal, with an overall mortality rate of nearly 90%, and the risk of subsequent rupture remains high, especially in large aneurysm diameters or progressive disease. Unfavorable neck anatomy in EVAR is linked to early graft failure and long-term complications. Recently, a novel multiple stiff wire (MSW) technique has been developed to overcome the challenges of hostile neck anatomy without introducing additional devices and procedural complexity. It has also been feasible in a series of elective cases. In this case, we report the first-ever utilization of the MSW technique in an emergency case of an acute contained rAAA with a conical-shaped, severely angulated neck who underwent Endovascular Aortic Repair (EVAR).

Case presentation

A 61-year-old man came with intermittent sharp stomach pain radiating to his back since three weeks ago. Physical examination showed elevated blood pressure and anemic conjunctiva. Laboratory examinations showed anemia, leukocytosis, elevated D-dimer level, high creatinine level, and low eGFR. CT-Scan Angiography (CTA) revealed severely hostile anatomy, a conical-shaped abdominal aorta aneurysm with a length of 13.2 cm and a maximum diameter of 9.3 cm with angulation of 90.1°. The patient was diagnosed with Ruptured AAA with a conical-shaped, severely angulated neck. Endovascular Aortic Repair (EVAR) management with MSW technique was planned for him. After four days, The patient was discharged in a clinically stable condition with optimal medical treatment and education.

Conclusion

The endovascular approach could be performed in emergency settings and has been proven to reduce length of stay, mortality, and morbidity rates. In this case, the endovascular approach with the MSW technique showed promising results for the patient.

Towards a reduced order model for EVAR planning and intra-operative navigation

INTRODUCTION

The pre-operative planning and intra-operative navigation of the endovascular aneurysm repair (EVAR) procedure are currently challenged by the aortic deformations that occur due to the insertion of a stiff guidewire. Hence, a fast and accurate predictive tool may help clinicians in the decision-making process and during surgical navigation, potentially reducing the radiations and contrast dose. To this aim, we generated a reduced order model (ROM) trained on parametric finite element simulations of the aortic wall-guidewire interaction.

METHOD

A Design of Experiments (DOE) consisting of 300 scenarios was created spanning over seven parameters. Radial basis functions were used to achieve a morphological parametrization of the aortic geometry. The ROM was built using 200 scenarios for training and the remaining 100 for validation.

RESULTS

The developed ROM estimated the displacement of aortic nodes with a relative error below 5.5% for all the considered validation cases. From a preliminary analysis, the aortic elasticity, the stiffness of the guidewire and the tortuosity of the cannulated iliac artery proved to be the most influential parameters.

CONCLUSIONS

Once built, the ROM provided almost real-time and accurate estimations of the guidewire-induced aortic displacement field, thus potentially being a promising pre- and intra-operative tool for clinicians.

Endovascular management of aortic aneurysm with severe neck angulation and/or iliac artery tortuosity using multiple stiff wire technique: a case series

Background

Suitable aortic neck is one of the essential components for thoracic endovascular aortic repair (TEVAR) and endovascular aortic repair (EVAR). Advanced techniques were developed to adjust and compromise the aneurysm neck angulation but with adding additional devices and complexity to the procedure. We proposed a simple technique to modify severe neck angulation and/or iliac artery tortuosity by using the multiple stiff wire (MSW) technique.

Method

Two femoral accesses were required for the MSW technique. A guidewire with a support catheter was inserted through the right and left femoral arteries and positioned in the abdominal or thoracic aorta. Wire exchanges were done with extra stiff wire in both femoral accesses. It can be considered to add multiple stiff wires to align the torturous neck / iliac artery. Delivery of the stent graft main body can be done via one of the accesses.

Result

Six patients with different aortic pathology were admitted to our hospital. Four patients undergo EVAR procedure and two patients undergo TEVAR procedure. All patients had aortic neck angulation problems with one patient having iliac artery tortuosity. MSW technique was performed on the patients with good results. Follow-up CTA after 3 months revealed a good stent position without stent migration and no endoleak was found in all but one patient.

Conclusion

MSW technique is a simple and effective technique to modify aortic neck/iliac artery angulation in TEVAR or EVAR procedure.

Adjunctive Procedures for Challenging Endovascular Abdominal Aortic Repair: When Needed and How Effective?

Endovascular aneurysm repair (EVAR) is now considered the first choice treatment modality for abdominal aortic aneurysm (AAA) treatment. Advocates for endovascular strategies will try to treat all AAA by EVAR, regardless if the anatomy is conducive for treatment or not. However, the long-term outcomes of EVAR outside the instructions for use (IFU) due to a hostile aneurysmal neck or iliac artery anatomy are known to be poor. The EVAR procedures can be classified according to the technical difficulty, IFU, and need for visceral revascularization: standard, adjunctive, and complex EVAR. The situation required for adjunctive procedures can be classified as the following four steps: a hostile neck (i.e., short or severely angled); large inferior mesenteric or lumbar artery; tough iliac artery anatomy, such as a short common iliac artery and stenotic external iliac artery; and limitations in vascular access. This article will discuss the adjunctive procedures to overcome hostile aneurysm neck and unsuitable iliac artery anatomy.

Successful Percutaneous Endovascular Repair in a Very Large, Symptomatic, Non-ruptured Abdominal Aortic Aneurysm with Severe Neck Angulation

Percutaneous endovascular aneurysm repair (PEVAR) is a minimally invasive treatment option for patients with abdominal aortic aneurysms (AAA). PEVAR allows for the lower incidence of vascular access site complications and decreased procedure time, yet the utility of this technique depends on the anatomical characteristics of the aneurysm. A detailed evaluation of the access site vessels and aneurysm neck anatomy are critical for standard patient and device selection. An 84-year-old male presented to our institution with the sudden onset of abdominal pain and confusion. Subsequent imaging demonstrated the presence of a 9.5 cm fusiform, infrarenal abdominal aortic aneurysm with a greater than 60-degree neck angulation and bilateral common iliac aneurysms. The patient underwent percutaneous endovascular aneurysm repair (PEVAR), and a type IB endoleak seen at the end of the case was treated successfully. At the one-year follow-up, the patient remained asymptomatic with the AAA stable in size.  This case represents the largest reported symptomatic unruptured AAA repaired with a completely percutaneous technique to date. Building up the stent-graft from the bifurcation with a unibody modular device may allow for support to address the severe angulation of a very hostile neck. PEVAR is a viable option in patients with symptomatic AAA and can be performed despite severe aneurysm neck angulation.