Intravascular Lithotripsy of Negatively Remodeled Calcified Abdominal Aorta to Facilitate Transfemoral Transcatheter Aortic Valve Replacement

Abstract

Background

Transfemoral access is the preferred route for transcatheter aortic valve replacement (TAVR), but severe calcification and luminal narrowing of the iliofemoral artery or abdominal aorta may preclude safe large-bore sheath passage. Intravascular lithotripsy (IVL) has been increasingly used for iliofemoral vessel preparation, yet its application in the abdominal aorta has been rarely reported.

Case Summary

An 84-year-old woman with symptomatic severe aortic stenosis was deemed high risk for transfemoral TAVR owing to severe narrowing with circumferential calcification of infrarenal aorta with luminal diameter <5 mm. To preserve transfemoral access, IVL with a 7.0-mm Shockwave balloon was performed using stepwise low-pressure inflations (1-6 atm, 300 pulses), achieving adequate luminal expansion for an 18-F sheath. A 23-mm self-expanding valve was successfully implanted without complications, and the patient was discharged the next day.

Discussion

This case demonstrates that IVL can safely modify a small-caliber, circumferentially calcified iliofemoral and abdominal aorta to facilitate transfemoral TAVR.

Take-Home Message

Stepwise low-pressure inflations and meticulous procedural planning may expand the feasibility of transfemoral access in patients otherwise considered for higher-risk alternative routes.

Visual Summary

Transfemoral access remains the default route for transcatheter aortic valve replacement (TAVR) owing to lower procedural risk and superior outcomes compared with alternative access strategies. However, stenosis of heavy calcification of iliofemoral or abdominal aortic segments can make transfemoral delivery unsafe, often necessitating transaxillary, transcaval, or transcarotid approaches. These are associated with higher complication rates. Intravascular lithotripsy (IVL) has emerged as an adjunct for vessel preparation in heavily calcified iliofemoral arteries, but its use in the abdominal aorta is rarely reported.¹ Here, we present a case where IVL in the distal abdominal aorta enabled transfemoral TAVR, with emphasis on technical considerations, safety principles, and the potential role of IVL in expanding transfemoral access for patients with otherwise prohibitive anatomy.

History of Presentation

An 84-year-old woman with symptomatic severe aortic stenosis was referred for TAVR evaluation. Over the preceding year, she developed progressive fatigue and occasional lightheadedness. Her exercise tolerance declined, with increased need for rest during daily activities, though she was still able to continue short daily walks.

Past Medical History

Her history was notable for coronary artery bypass grafting with a left internal mammary artery graft to the left anterior descending artery and 2 saphenous vein grafts, paroxysmal atrial fibrillation requiring anticoagulation, bilateral carotid endarterectomy, right groin arteriovenous fistula, hypertension, hyperlipidemia, diabetes mellitus, obstructive sleep apnea, prior gastrointestinal bleeding, and stage 3 chronic kidney disease.

Investigations

Transthoracic echocardiography demonstrated severe aortic stenosis with a mean gradient of 42 mm Hg and valve area of 0.7 cm². Multidetector computed tomography (CT) confirmed a small native aortic annulus with an area of 274 mm², consistent with a small annular anatomy. CT angiography revealed circumferential heavy calcification of the infrarenal abdominal aorta with a minimal luminal diameter of 4.9 × 5.7 mm (mean 5.3 mm) and an external diameter of <10 mm (mean 9.1 mm), consistent with calcified abdominal aorta stenosis with negative remodeling. Bilateral common iliac arteries were also severely narrowed (right 5.3 mm mean, left 4.7 mm mean) with eccentric calcification (Figure 1). These findings identified the abdominal aorta and iliac arteries as the principal barriers to transfemoral access.

Figure 1.

Computed Tomography Angiography

(A) Circumferential heavy calcification of the infrarenal abdominal aorta with a minimal luminal diameter of 4.9 × 5.7 mm (mean 5.3 mm). (B and C) bilateral common iliac arteries were also narrowed, measuring 4.3 × 6.2 mm on the right and 2.7 × 6.7 mm on the left, with eccentric calcification. (D) The external diameter of the abdominal aorta measured 8.6 × 9.5 mm (mean 9.1 mm).

Management Strategy

To preserve transfemoral access, IVL of the infrarenal aorta and right iliac artery was planned using an undersized balloon and stepwise low-pressure inflations. If unsuccessful, alternative access was prepared as a bailout strategy.

Procedure

After obtaining informed consent, the procedure was performed in a catheterization laboratory. The right common femoral artery was accessed under combined ultrasound and fluoroscopic guidance, and an 8-F sheath was inserted. In addition, the right radial artery was cannulated with a 6-F Glidesheath Slender under ultrasound guidance.

Angiography confirmed severe stenosis and heavy circumferential calcification of the distal abdominal aorta and common iliac arteries (Figure 2A), consistent with preprocedural CT angiography findings. To facilitate safe passage of a large-bore sheath, IVL was performed using a Shockwave M5+ 7.0 × 60 mm balloon (Johnson & Johnson MedTech). Sequential inflations were delivered, beginning at 1 to 2 atm and gradually increasing to 4 to 6 atm, for a total of 10 cycles (30 pulses per cycle), resulting in adequate luminal expansion (Figure 3).

Figure 2.

Angiography of Abdominal Aorta and Iliac Arteries

(A) Baseline angiography before intravascular lithotripsy, demonstrating significant stenoses (arrowheads). (B) Final angiography after intravascular lithotripsy demonstrating improved luminal expansion.

Figure 3.

Intravascular Lithotripsy

Intravascular lithotripsy of the distal abdominal aorta (A) and right common iliac artery (B).

Following IVL, the femoral sheath was exchanged for an 18-F Gore DrySeal sheath (W. L. Gore & Associates, Inc), which was successfully advanced without resistance. A 0.035-inch SavvyWire was positioned across the stenotic surgical bioprosthetic aortic valve into the left ventricle. A 23-mm Medtronic Evolut FX + valve (Medtronic) was then advanced to the annulus and deployed under rapid ventricular pacing. Postdeployment aortography (Figure 4) and transthoracic echocardiography confirmed appropriate prosthesis expansion, a low residual transvalvular gradient, and absence of paravalvular leak.

Figure 4.

Aortic Root Angiography Following Transcatheter Aortic Valve Replacement

Final angiography of the abdominal aorta and iliac arteries demonstrated no evidence of vascular complications (Figure 2B). Hemostasis was secured using an 18-F MANTA closure device (Teleflex) at the femoral access site and a radial compression device at the radial access site. The patient tolerated the procedure well and was discharged the following day in stable condition.

Discussion

Severe calcification of the iliofemoral or abdominal aorta is a recognized challenge for transfemoral TAVR, often precluding large-bore sheath passage and necessitating alternative access strategies such as transaxillary, transcaval, or transcarotid approaches. Although these alternatives are feasible, they are associated with higher complication rates and less favorable outcomes compared with transfemoral access. Preserving the transfemoral route is therefore of great clinical importance whenever possible.

IVL has recently emerged as a valuable adjunctive tool to facilitate transfemoral TAVR in patients with heavily calcified iliofemoral arteries. By delivering acoustic shockwaves through a low-pressure balloon, IVL produces microfractures in calcium while minimizing barotrauma to soft tissue. This mechanism improves vessel compliance without the rupture risk associated with conventional high-pressure angioplasty. Multiple registries and case series have demonstrated the feasibility and safety of IVL for iliofemoral access preparation.¹

In contrast, the use of IVL in the abdominal aorta has been infrequently reported, with only a few case reports describing its application in settings such as coral reef aorta.^2,3 The unique aspect of our case is the presence of circumferential atherosclerotic calcification with negative remodeling of the infrarenal abdominal aorta, characterized by an external diameter of only approximately 9 mm and a lumen of approximately 5 mm. This small-caliber phenotype, resulting from constrictive vessel remodeling, contrasts with previously reported cases. It highlights a distinct pattern of advanced atherosclerosis that may be particularly relevant in elderly patients with multiple comorbidities.⁴

In this challenging anatomy, IVL permitted controlled vessel expansion at low balloon pressures, reducing rupture risk compared with high-pressure angioplasty and enabling safe transfemoral TAVR. Several technical considerations are noteworthy: 1) careful balloon sizing, with a 7.0-mm balloon selected to match the narrowed lumen and avoid oversizing; 2) gradual, stepwise low-pressure inflations to minimize vessel injury; and 3) comprehensive bailout planning, including availability of covered stents and surgical backup. These precautions are critical when applying IVL to large central vessels such as the abdominal aorta, where complications could be catastrophic.

When performing IVL for iliofemoral or aortoiliac preparation, it is important to position the large-bore sheath above the treated segment whenever possible. This prevents the valve delivery system from interacting with the modified calcified zone, reducing the risk of vessel injury or device entrapment during advancement or withdrawal.

In this case of native aortic stenosis with extensive aortoiliac calcification, a self-expanding Evolut FX + valve was selected owing to its flexible over-the-wire delivery catheter and tapered distal profile, which facilitated smoother advancement through the IVL-treated aortic segment. Preprocedural CT demonstrated a small annular area, consistent with a small native aortic annulus. This anatomy further supported the use of a self-expanding, supra-annular valve design, which provides a larger effective orifice area and lower residual gradients compared with intra-annular balloon-expandable valves in small annuli. Although the Evolut system is typically advanced without an introducer sheath, an 18-F Gore DrySeal sheath was intentionally used in this case to provide additional hemostasis and procedural stability and to protect the IVL-modified aortic segment during catheter exchanges.

Clinically, this case demonstrates that IVL can extend the feasibility of transfemoral TAVR in anatomically prohibitive patients. Recent data indicate that transfemoral TAVR with adjunctive peripheral intervention is associated with more favorable outcomes compared with nontransfemoral approaches, highlighting the importance of preserving transfemoral access whenever possible.⁵ Although early results are encouraging, systematic data are lacking. Further studies are needed to define the safety, durability, and long-term outcomes of abdominal aortic IVL in this setting.

Conclusions

This case demonstrates that IVL of the abdominal aorta can be performed safely and effectively to facilitate transfemoral TAVR in patients with prohibitive calcification and small-caliber anatomy. Using an undersized balloon with gradual low-pressure inflations allowed controlled vessel expansion, enabling large-bore sheath delivery without vascular injury. Careful patient selection, meticulous planning, and preparedness for bailout remain essential when applying IVL to central vessels, where complications could be catastrophic. Although this single case illustrates feasibility, further experience and systematic data are needed to define the role of abdominal aortic IVL in expanding transfemoral access options.

Visual Summary.

Severe Circumferential Calcification and Negative Remodeling of Abdominal Aorta Resulted in Prohibitive Transfemoral Access

Intravascular lithotripsy (IVL) of the abdominal aorta and common iliac artery increased luminal diameter, enabling safe device passage and successful transfemoral transcatheter aortic valve replacement (TAVR) with deployment of a 23-mm self-expanding valve.

Funding Support and Author Disclosures

The authors have reported that they have no relationships relevant to the contents of this paper to disclose.

Take-Home Messages

• •Severe abdominal aortic calcification may prohibit transfemoral access for TAVR.
• •IVL at low pressures can safely modify calcified abdominal aorta and facilitate large-bore sheath delivery.
• •Careful patient selection, undersized balloon strategy, and comprehensive bailout planning are essential to minimize procedural risk.