Ipsilateral Iliac Branch Repair Using a Looped Wire,Precannulated Gate Technique

Introduction

Embolization of the internal iliac artery, with endograft extension into the external iliac, has been described as a strategy to achieve distal seal during endovascular aortic aneurysm repair (EVAR) when there is no adequate landing zone in the common iliac artery.^1,2 However, occlusion of hypogastric blood flow can lead to long-term sequelae such as buttock claudication, sexual dysfunction, and pelvic ischemia.^3–6 Additionally, the hypogastric artery provides important collateral flow to the spinal cord during complex endovascular aortic procedures. ⁷ Preservation of hypogastric blood flow is therefore desirable whenever possible, a stance also taken by the Society for Vascular Surgery (SVS). ⁸

The Gore Iliac Branch Excluder (IBE; W.L. Gore & Associates, Flagstaff, AZ, USA) is a modular, bifurcated device that allows preservation of the internal iliac artery in such clinical situations. Results from the IBE pivotal clinical trial demonstrated 95.1% patency of the internal branch component, with no incidence of buttock claudication or sexual dysfunction. ⁹ Although other iliac branch devices are available for preservation of the internal iliac artery outside the United States, the Gore IBE is currently the only such device approved by the US Food and Drug Administration (FDA).

Delivery of the IBE device is via ipsilateral femoral access. Following partial deployment, the internal gate is generally cannulated from the contralateral side, after snaring a through-wire over the aortic bifurcation. This becomes challenging in the setting of prior endovascular or open aortic repair, due to the difficulty of sheath delivery up and over the flow divider. One solution to this problem has been to cannulate and deliver the internal iliac component through an upper extremity access, but this introduces additional potential morbidity, including access site complications and stroke, as well as limitations related to device length. ¹⁰ Herein described a novel technique to deliver the internal iliac component via the ipsilateral femoral access site, utilizing a looped wire to precannulate the internal gate and obviating the need for upper extremity or contralateral femoral access.

Technique

Ultrasound-guided percutaneous access is obtained on the side of the iliac aneurysm, and 2 Perclose devices are deployed using the preclose technique. Alternatively, open surgical exposure can be performed. Over a stiff wire, the access is upsized to a 16F sheath in order to accommodate the main body IBE device. The sheath is advanced into the prior endograft or surgical graft limb, well above the intended position of the IBE. The stiff wire is removed, and a looped Glide wire (Terumo Medical, Somerset, NJ, USA) is advanced through the sheath, maintaining both ends externally (Figure 1). The IBE device is then loaded onto both ends of the wire (Figure 2A), which establishes through-wire access over the IBE flow divider and into the internal iliac gate (Figure 2B). The IBE device is advanced over the looped wire and positioned, the sheath is withdrawn, and the IBE deployed. The entire ipsilateral limb must be deployed at this point, to allow access through the external iliac limb.

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Figure 1.

Insertion of looped wire. A Glide wire is inserted from its middle point, maintaining both ends externally. This is made easier by utilizing a smaller, 11-cm sheath as an introducer (A). The looped wire is then advanced up through the 16-F Dry Seal sheath into the prior graft (B).

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Figure 2.

Loading and delivering the iliac branch device. The Iliac Branch Endoprosthesis (IBE) is loaded over both ends of the looped wire (A). Following deployment, this provides through-wire access over the IBE flow divider and into the internal gate (B).

Next, over the external iliac end of the through wire, a sheath is advanced over the flow divider and positioned into the internal iliac gate (Figure 3). This can be successfully achieved with an 8.5-F Oscor Destino steerable sheath (Oscor, Palm Harbor, FL, USA), as well as a 9-F Flexor Raabe sheath (Cook Medical, Bloomington, IN, USA). With the latter approach, the through-wire can be exchanged for an 0.014-inch wire in order to anchor the sheath in place and still accommodate the internal iliac component in parallel.

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Figure 3.

Sheath delivery. The sheath is advanced over the through-wire and seated on the iliac flow divider.

The sheath is double-punctured, and the internal iliac artery is selected using a Glide wire and Glide catheter (Terumo Medical, Somerset, NJ) (Figure 4). The internal iliac wire is then exchanged for a Rosen wire, and a Viabahn VBX balloon expandable stent is advanced into position and deployed (Figure 5).

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Figure 4.

Cannulation of the internal iliac artery. The internal iliac artery is cannulated through the gate, and the wire replaced with a stiffer Rosen wire.

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Figure 5.

Introduction and deployment of internal component. A VBX balloon-expandable stent graft is advanced into position and deployed (left). Completion angiogram demonstrates successful exclusion of the common iliac, with good perfusion through the internal branch (right).

We have now successfully performed this technique in 4 patients. There have been no endoleaks, branch occlusions, or other complications noted at 30-day follow-up (Table 1).

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Table 1.

Patients Treated Using the Ipsilateral Iliac Branch Technique. ^a

Patient	Age, y/Sex	Prior Aortic Intervention	Sheath	Internal Component	Technical Success	Branch patency	Endoleak
1	65/male	EVAR	8.5-F Oscor	8L × 59 mm VBX	Yes	Yes	No
2	88/male	EVAR	8.5-F Oscor	8L × 79 mm VBX 11 × 39 mm VBX	Yes	Yes	No
3	69/male	EVAR	9-F Raabe	11 × 59 mm VBX	Yes	Yes	No
4	69/male	OAR	8.5-F Oscor	8L × 59 mm VBX (×2)	Yes	Yes	No

Abbreviations: EVAR, endovascular aortic aneurysm repair; OAR, open aortic aneurysm repair; VBX, Viabahn Balloon Expandable stent graft.

a

Technical success defined as delivery of internal component and aneurysm seal. Branch patency and endoleak reported at 30-day follow-up.

Discussion

Preservation of hypogastric blood flow during endovascular aortic and iliac aneurysm repair is important to prevent buttock claudication and sexual dysfunction and to maintain important spinal cord collaterals. While the Gore IBE device has provided an FDA-approved solution for this, its use in the setting of prior EVAR or open aortic repair can be challenging. This technique provides a novel solution to maintain internal iliac patency that takes advantage of the precannulated internal iliac gate and eliminates the need for upper extremity access or contralateral femoral access across the steep flow divider.

Late degeneration of iliac vessels following EVAR is a well-described phenomenon.^11,12 This is especially true in cases where flared or “bell-bottom” iliac limbs were used at the index EVAR procedure in order to seal in ectatic or even aneurysmal iliac landing zones,^13,14 leaving patients at risk for development of type Ib endoleaks and aneurysm rupture. Of course, the best practice is to consider iliac branch use at the time of EVAR whenever the common iliac artery is significantly dilated. When patients do present with these late complications, however, this technique allows rapid access to the internal iliac gate and can potentially be used in both elective and emergent settings.

There are several technical aspects of the procedure that deserve special attention and discussion. First, the use of steerable sheaths such as the Oscor Destino or TourGuide (Medtronic, Santa Rosa, CA, USA) allow smooth navigation of the hairpin turn over the IBE bifurcation, making use of the preloaded through wire into the internal gate. With the 8.5-F sheaths, the through-wire must be removed in order to accommodate a VBX covered stent. While we have not found this to be an issue because of the support of the steerable sheath and the deliverability of the VBX stent, there is a theoretical concern for the sheath “kicking out” when it is not anchored by the through wire. Alternatively, upsizing to a 9-F sheath, such as the Cook Flexor (Cook Medical, Bloomington, IN), allows the operator to maintain the through-wire alongside the stent to anchor the sheath in place.

As previously alluded to, navigating the tight turn over the IBE flow divider can be difficult. While our general practice with IBE is to deliver the internal component over a 1-cm tip Amplatz wire, the Amplatz does not track well through this setup. We have therefore preferred to use a Rosen wire, which provides a reasonable compromise between stiffness and trackability. Again, the high trackability of the VBX is of critical importance; the standard IBE internal component is not only much stiffer but also requires a 12-F sheath for delivery.

There are several potential disadvantages to this approach. The entire external iliac limb must be deployed prior to gate cannulation, dissociating the IBE from its delivery system. This precludes any further adjustments in cases of difficult cannulation, and introduces the potential for device malposition and migration. Additionally, because the internal component is delivered through the external iliac limb over a single wire, the technique does not lend itself to performing “kissing balloon” dilation of both the internal and external iliac stents. Finally, this technique and use of the VBX stent to complete the internal iliac limb represent off-label use of the IBE device, and IBE deployment over a soft wire is outside the instructions for use for both the device and the wire.

Conclusion

This novel looped wire technique, performed via an ipsilateral femoral approach, is a useful alternative that eliminates the need for upper extremity or contralateral femoral artery access during distal endograft extension using the IBE device.